Answer:
100J
Explanation:
50N*20m=100J
N*m=J(joule)
A 52 kg and a 95 kg skydiver jump from an airplane at an altitude of 4750 m, both falling in the pike position. Assume all values are accurate to three significant digits. (Assume that the density of air is 1.21 kg/m3 and the drag coefficient of a skydiver in a pike position is 0.7.) If each skydiver has a frontal area of 0.14 m2, calculate their terminal velocities (in m/s). 52 kg skydiver m/s 95 kg skydiver m/s How long will it take (in s) for each skydiver to reach the ground (assuming the time to reach terminal velocity is small)
Answer: 52 kg skydiver: 9.09 m/s and 522.55 s
95 kg skydiver: 12.3 m/s and 386.2 s
Explanation: Drag Force is an opposite force when an object is moving in a fluid.
For skydivers, when falling through the air, the forces acting on it are gravitational and drag forces. At a certain point, drag force equals gravitational force, which is constant on any part of the planet, producing a net force that is zero. Since there is no net force, there is no acceleration and, consequently, velocity is constant. When that happens, the person reached the Terminal Velocity.
Drag Force and Velocity are proportional to the squared speed. So, terminal velocity is given by:
[tex]F_{G}=F_{D}[/tex]
[tex]mg=\frac{1}{2}C \rho Av_{T}^{2}[/tex]
[tex]v_{T}=\sqrt{\frac{2mg}{\rho CA} }[/tex]
where
m is mass in kg
g is acceleration due to gravitational force in m/s²
ρ is density of the fluid in kg/m³
C is drag coefficient
A is area of the object in the fluid in m²
Calculating:
The 52kg skydiver has terminal velocity of:
[tex]v_{T}=\sqrt{\frac{2(52)(9.8)}{(1.21)(0.7)(0.14)} }[/tex]
[tex]v_{T}=[/tex] 9.09
The 95kg skydiver's terminal velocity is
[tex]v_{T}=\sqrt{\frac{2(95)(9.8)}{(1.21)(0.7)(0.14)} }[/tex]
[tex]v_{T}=[/tex] 12.3
The 52 kg and 95kg skydivers' terminal velocity are 9.09m/s and 12.3m/s, respectively.
The time each one will reach the floor will be:
52 kg at 9.09 m/s:
[tex]t=\frac{4750}{9.09}[/tex]
t = 522.5
95 kg at 12.3 m/s:
[tex]t=\frac{4750}{12.3}[/tex]
t = 386.2
The 52 kg and 95kg skydivers' time to reach the floor are 522.5 s and 386.2 s, respectively.
For these pictures is more or less friction needed?
Answer:
8: More
9: More
10: More
11: Less
12: Less
12: More
Count how many significant figures each of the quantities below has:
a. 2.590 km
b.12.303 ml
c. 7800kg
Explain how an electron emitted by the photoelectric effect can have kinetic energy less than threshold energy ?
Answer:
the photons (quanta of light) collide with the electrons, these electrons have to overcome the threshold energy that is the energy of union with the metal, and the energy that remains is converted to kinetic energy.
K = E - Ф
Explanation:
The photoelectric effect is the emission of electrons from the surface of a metal.
This was correctly explained by Einstein, in his explanation the energy of the photons (quanta of light) collide with the electrons, these electrons have to overcome the threshold energy that is the energy of union with the metal, and the energy that remains is converted to kinetic energy.
E = hf
E = K + Ф
K = E - Ф
The energy of the photons is given by the Planck relation E = hf and according to Einstein the number of joints must be added
E = n hf
Therefore, depending on the value of this energy, the emitted electrons can have energy from zero onwards.
Four identical metallic objects carry the following charges 1.82 6.65 4.80 and 9.30 C The objects are brought simultaneously into contact so that each touches the others Then they are separated a What is the final charge on each object b How many electrons or protons make up the final charge on each object
Answer:
a) 5.64 C
b) 3.5*10¹⁹ protons
Explanation:
a)
Since the four metallic objects are identical, and total charge must be conserved, this means that after brought simultaneously into contact so that each touches the others, once separated, total charge must be the same than before being brought in contact.But due they are identical, after charges were able to transfer freely between them, the four objects must have the same final charge, i.e. the fourth part of the total charge, as follows:[tex]Q_{n} = \frac{Q_{tot}}{4} = \frac{22.57C}{4} = 5.64 C (1)[/tex]
b)
This charge will be divided between n protons, since the charge is positive.Since each proton carries a charge equal to the elementary charge e, which value is 1.6*10⁻¹⁹ C, we can find the number of protons in excess, doing the following calculation: [tex]n_{p} =\frac{Q_{n}}{e} = \frac{5.64C}{1.6e-19C} = 3.5 e19 C (2)[/tex]AYUDA!!!!!
Si 300 cm de alcohol tienen una masa de 237 g
calcular:
a) El valor de su densidad expresada en g/cm'y en kg/m?
b) su peso específico expresado en N/m?
Answer:
a) El valor de la densidad es 0.79 [tex]\frac{g}{cm^{3} }[/tex] o 790 [tex]\frac{g}{cm^{3} }[/tex]
b) El peso especifico es 7749.9[tex]\frac{N}{m^{3} }[/tex]
Explanation:
a) La densidad se define como la propiedad que tiene la materia, ya sean sólidos, líquidos o gases, para comprimirse en un espacio determinado. En otras palabras, la densidad es una magnitud que permite medir la cantidad de masa que hay en determinado volumen de una sustancia. Entonces, la expresión para el cálculo de la densidad es el cociente entre la masa de un cuerpo y el volumen que ocupa:
[tex]d=\frac{m}{V}[/tex]
En este caso:
masa= 237 g= 0,237 kg (siendo 1000 g= 1 kg)volumen= 300 cm³= 0,0003 m³ (siendo 1 cm³= 0,000001 m³)Reemplazando:
[tex]d=\frac{237 g}{300cm^{3} }[/tex] → d=0.79 [tex]\frac{g}{cm^{3} }[/tex]
[tex]d=\frac{0,237 kg}{0,0003m^{3} }[/tex]→ d=790 [tex]\frac{g}{cm^{3} }[/tex]
El valor de la densidad es 0.79 [tex]\frac{g}{cm^{3} }[/tex] o 790 [tex]\frac{g}{cm^{3} }[/tex]
b) El peso específico es la relación existente entre el peso y el volumen que ocupa una sustancia en el espacio.
Entonces, en este caso, siendo el peso:
P= m*g= 0,237 kg* 9,81 [tex]\frac{m}{s^{2} }[/tex]= 2,32497 N
el peso especifico es calculado como:
[tex]Pe=\frac{Peso}{Volumen}= \frac{2,32497N}{0,0003 m^{3} }[/tex]
Pe= 7749.9[tex]\frac{N}{m^{3} }[/tex]
El peso especifico es 7749.9[tex]\frac{N}{m^{3} }[/tex]
a toy train is moved towards a magnet that cannot move. what happens to the potential energy in the system of magnets during the movement
Answer:
Dakota moves a magnetic toy train toward a magnet that cannot move. What happens to the potential energy in the system of magnets during the movement? The potential energy increases because the train moves against the magnetic force. The potential energy decreases because the train moves against the magnetic force.
I hope this helps you :)
Se desea elevar un cuerpo de 1000 kg utilizando una elevadora hidráulica de plato grande circular de 50 cm de radio y plato pequeño circular de 8cm de radio, calcula: a) El peso del cuerpo. b) Cuanta fuerza hay que hacer en el émbolo pequeño, c) Si el émbolo pequeño desciende 60 cm, ¿qué volumen de fluido desplaza hacia el émbolo mayor?
Answer:
a) [tex]W=9810\: N[/tex]
b) [tex]F_{1}=251.14\: N[/tex]
c) [tex]V_{g}=0.012\: m^{3}[/tex]
Explanation:
a)
El peso del cuerpo es:
[tex]W=mg[/tex]
g es la gravedad (9.81 m/s²)
[tex]W=1000*9.81[/tex]
[tex]W=9810\: N[/tex]
b)
Usando el principio de Pascal tenemos:
[tex]P_{1}=P_{2}[/tex]
y la presion es la fuerza sobre el area.
[tex]\frac{F_{1}}{A_{1}}=\frac{F_{2}}{A_{2}}[/tex]
F(1) es la fuerza aplicada en el embolo pequeñoA(1) es el area del disco pequeñoF(2) es la fuerza aplicada en el embolo grandeA(2) es el area del disco grandeDespejando F(1):
[tex]F_{1}=F_{2}\frac{A_{1}}{A_{2}}[/tex]
el area del plato es: [tex]A=\pi R^{2}[/tex]
[tex]F_{1}=F_{2}\frac{\pi R_{1}^{2}}{\pi R_{2}^{2}}[/tex]
[tex]F_{1}=F_{2}\frac{R_{1}^{2}}{R_{2}^{2}}[/tex]
F(2) es el peso del cuerpo de 1000 kg (W)
[tex]F_{1}=9810\frac{8^{2}}{50^{2}}[/tex]
Por lo tanto, la fuerza que se debe hacer es:
[tex]F_{1}=251.14\: N[/tex]
c)
Como tenemos un sistema cerrado el volumen de agua que desciende por el embolo pequeño debe ser igual al que sube por el grande, por lo tanto:
[tex]V_{p}=V_{g}[/tex]
Vp es el volumen de agua en el émbolo pequeño
Vg es el volumen de agua en el émbolo grande
Como sabemos que son cilindros (V=πR²h)
[tex]\pi R^{2}h=V_{g}[/tex]
Entonces el volumen del émbolo mayor será:
[tex]V_{g}=\pi 0.08^{2}0.6[/tex]
[tex]V_{g}=0.012\: m^{3}[/tex]
Espero te haya sido de ayuda!
A 4.00-m-long, 470 kg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 75.0 kg construction worker stands at the far end of the beam. For the steps and strategies involved in solving a similar problem, you may view a Video Tutor Solution. What is the magnitude of the torque about the point where the beam is bolted into place?
Answer:
12164.4 Nm
Explanation:
CHECK THE ATTACHMENT
Given values are;
m1= 470 kg
x= 4m
m2= 75kg
Cm = center of mass
g= acceleration due to gravity= 9.82 m/s^2
The distance of centre of mass is x/2
Center of mass(1) = x/2
But x= 4 m
Then substitute, we have,
Center of mass(1) = 4/2 = 2m
We can find the total torque, through the summation of moments that comes from both the man and the beam.
τ = τ(1) + τ(2)
But
τ(1)= ( Center of m1 × m1 × g)= (2× 470× 9.81)
= 9221.4Nm
τ(2)= X * m2 * g = ( 4× 75 × 9.81)= 2943Nm
τ = τ(1) + τ(2)
= 9221.4Nm + 2943Nm
= 12164.4 Nm
Hence, the magnitude of the torque about the point where the beam is bolted into place is 12164.4 Nm
Scott travels north 3 Km and then goes west 3 Km before coming straight
back south 3 km. What is his displacement? *
9 Km
3 km, W
3 Km, E
9 km, S
Answer:
you have to times them all ti get the answer
Wind is formed when hot air rises and cool air sinks. This process is called __________
conduction
insulation
radiation
convection
plsssssssss answer this correct i put in 12 points and i will give you brainliest if you answer correct
Answer:
conduction is the correct answer
Learning Task 2:
Match the Richter magnitude indicated in column A with the
earthquake effect found in column B. Write your answer on the space provided.
NEED TONIGNT SANA MAY TUMULONG
Answer:
Hello your question has some missing parts attached below is the missing part
Answer :
Caused severe damage ( 7 ) ----- EFurniture moves ( 5 ) -------- GMay not be felt ( 2 ) ---------- FFelt by most people ( 4 ) --------- Dwidespread destruction ( 8 up ) ------ Blead to a lot of damage ( 6 ) -------- AFelt little by people ( 3 ) ---------- CExplanation:
Matching the Richter magnitude indicated in column A with the Earthquake effect found in column B
Caused severe damage ( 7 ) ----- EFurniture moves ( 5 ) -------- GMay not be felt ( 2 ) ---------- FFelt by most people ( 4 ) --------- Dwidespread destruction ( 8 up ) ------ Blead to a lot of damage ( 6 ) -------- AFelt little by people ( 3 ) ---------- CTwo resistors ( 3 ohms & 6 ohms) in a series circuit with a power supply = 12 volts. The current through resistor 6 ohms is :
a.
1.33 A
b.
2.66 A
c.
12 A
In a series circuit . . .
-- The total resistance is the sum of the individual resistors.
-- The current is the same at every point in the circuit.
The total resistance in this circuit is (3Ω + 6Ω ) = 9Ω
The current at every point is (V/R) = (12v / 9Ω ) = 1.33 A .
Pick choice (a).
The current flowing through the 6 Ohms resistor is: a. 1.33 A
Given the following data:
Resistor A = 3 Ohms.Resistor B = 6 Ohms.Voltage = 12 Volts.To find the current flowing through the 6 Ohms resistor:
First of all, we would determine the total equivalent resistance of the resistors connected in series.
[tex]T_eq = Resistor \; A + Resistor\; B\\\\T_eq = 3 + 6[/tex]
Total equivalent resistance = 9 Ohms
Note: The current flowing through both resistors are the same since they are connected in series.
From Ohm's law, we have:
[tex]Current = \frac{Voltage}{Resistor}\\\\Current = \frac{12}{9}[/tex]
Current = 1.33 Amperes
Therefore, the current flowing through the 6 Ohms resistor is 1.33 Amperes.
i need this literally asap
which of these statements are true?
1. it is always correct to use a 3 Amp fuse.
2. Fuses come in several different sizes and values
3. A fuse can be re-set and used again
4. A fuse once ‘blown’ needs replacing
5. Fuses are the ‘weak point’ in a circuit
Answer:
I only know number 4 is correct
Explanation:
what specific heat of water explains why the climate doesn't vary much with season in places near large body water
Answer:
The specific heat of water is greater than that of dry soil, therefore water both absorbs and releases heat more slowly than land. ... This causes land areas to heat more rapidly and to higher temperatures and also cool more rapidly and to lower temperatures, compared to oceans.
Explanation:
Liquid water is nearly 1,000 times denser than air. Thus, for every 32.0 feet (9.75 m) a scuba diver descends below the water's surface, the pressure increases by 1.00 atm. Human lungs have a volume of approximately 3.50 L. If a scuba diver descends to a depth of 80.0 feet where the pressure is 3.50 atm (2.50 atm from the water and 1.00 atm from the air pressure), then by how much does the volume of a 3.50 L surface sample of air decrease
Answer:
ΔV = -2.1 L
Explanation:
To solve this exercise we can use the ideal gas equation for two points
PV = nRT
P₁V₁ = P₂ V₂
where point 1 is on the surface and point 2 is at the desired depth,
V₂ = [tex]\frac{P_1}{P_2} \ V_1[/tex]
let's calculate
V₂ = ( [tex]\frac{1 atm}{2.5 atm}[/tex] ) 3.5 L
V₂ = 1.4 L
this is the new volume, the change in volume is
ΔV = V₂ -V₁
ΔV = 1.4-3.5
ΔV = -2.1 L
A 0.73-m aluminum bar is held with its length parallel to the east-west direction and dropped from a bridge. Just before the bar hits the river below, its speed is 20 m/s, and the emf induced across its length is 7.9 x 10-4 V. Assuming the horizontal component of the Earth's magnetic field at the location of the bar points directly north, (a) determine the magnitude of the horizontal component of the Earth's magnetic field, and (b) state whether the east end or the west end of the bar is positive.
Answer:
A) B = 5.4 10⁻⁵ T, B) the positive side of the bar is to the West
Explanation:
A) For this exercise we must use the expression of Faraday's law for a moving body
fem = [tex]- \frac{d \phi }{dt}[/tex]
fem = [tex]- \frac{d (B l y}{dt}= - B l v[/tex]- d (B l y) / dt = - B lv
B = [tex]- \frac{fem}{l \ v}[/tex]
we calculate
B = - 7.9 10⁻⁴ /(0.73 20)
B = 5.4 10⁻⁵ T
B) to determine which side of the bar is positive, we must use the right hand rule
the thumb points in the direction of the rod movement to the south, the magnetic field points in the horizontal direction and the rod is in the east-west direction.
Therefore the force points in the direction perpendicular to the velocity and the magnetic field is in the east direction; therefore the positive side of the bar is to the West
Particle A and particle B are held together with a compressed spring between them. When they are released, the spring pushes them apart, and they then fly off in opposite directions, free of the spring. The mass of A is 8.00 times the mass of B, and the energy stored in the spring was 73 J. Assume that the spring has negligible mass and that all its stored energy is transferred to the particles. (a) Once that transfer is complete, what is the kinetic energy of particle A
Answer:
K_a = 8,111 J
Explanation:
This is a collision exercise, let's define the system as formed by the two particles A and B, in this way the forces during the collision are internal and the moment is conserved
initial instant. Just before dropping the particles
p₀ = 0
final moment
p_f = m_a v_a + m_b v_b
p₀ = p_f
0 = m_a v_a + m_b v_b
tells us that
m_a = 8 m_b
0 = 8 m_b v_a + m_b v_b
v_b = - 8 v_a (1)
indicate that the transfer is complete, therefore the kinematic energy is conserved
starting point
Em₀ = K₀ = 73 J
final point. After separating the body
Em_f = K_f = ½ m_a v_a² + ½ m_b v_b²
K₀ = K_f
73 = ½ m_a (v_a² + v_b² / 8)
we substitute equation 1
73 = ½ m_a (v_a² + 8² v_a² / 8)
73 = ½ m_a (9 v_a²)
73/9 = ½ m_a (v_a²) = K_a
K_a = 8,111 J
can someone explain how to find the tangent line of something :D
Answer:
This can help you! Pictures tell more than 100s of word.
Explanation:
Consider the situation||: A child pulls a sled by a rope across the lawn at a constant speed. Of the forces listed, identify which act upon the sled.
Normal, Gravity, Applied, Friction, Tension, & Air Resistance
Answer:
Gravitational
Tension
Normal
Friction.
Explanation:
The forces acting on the sled are:
Tension: the tension from the rope, this is the force that "moves" the sled.
Friction: kinetic friction between the sled and the ground as the sled moves.
There are another two forces that also act on the sled, but that "has no effect"
Gravitational force: This force pulls the sled down, against the floor.
Normal force: This force "opposes" to the gravitational one, so they cancel each other.
These two forces cancel each other, so they have no direct impact on the movement of the sled. BUT, the friction force depends on the weight of the moving object, and the weight of the moving object depends on the gravitational force, so we need gravitational force in order to have friction force.
Then we can conclude that the forces acting on the sled are:
Gravitational
Tension
Normal
Friction.
Lex launched a golfball with his lego catapult. It traveled 7 meters and was in the air for 2 seconds. Please determine the object’s maximum height, horizontal velocity, vertical velocity, actual velocity, and time it reached its maximum height. The angle of release (the catapult’s arm) is 40°.
Horizontal Velocity = vx
Vertical Velocity = V1y
Actual Velocity: V1 = Vactual
Time reached highest point
Height reached!= h
Givens:
dx=
a=
t=
Angle of release:
Table B:
What you need to determine
Formula used
Answer: remember to label the correct units
Distance
Measure it with a meter stick
Time Traveled
Measure it with a stopwatch
Horizontal Velocity
Vertical Velocity
Actual Velocity
Time reached Highest Point
What was the object’s highest point
Answer:
Explanation:
Range R = 7 m
angle of projection θ = 40⁰
u² sin2θ / g = R where u is velocity of throw.
u² sin 80 / g = 7
u² = 69.71
u = 8.35 m/s
horizontal velocity = u cos 40 = 8.35 cos 40
= 6.4 m /s
vertical velocity = u sin 40 = 8.35 sin40
= 5.37 m /s
Maximum height :-
v² = u² - 2gh , u is initial vertical component of throw.
0 = 5.37² - 2 x 9.8 x h
h = 1.47 m
Time to reach max height :--
v = u - gt
o = 5.37 - 9.8 t
t = .55 s
Part A: A group of students performed the same "Ohm's Law" experiment that you did in class. They obtained the following results:
Trial V (volts) I (mA)
1 1.00 7.2
2 2.10 14.0
3 3.10 20.7
4 4.00 27.2
5 4.90 32.2
Determine the slope and y-intercept of the graph, and report these values below. (
Part B: Your mischievous lab partner takes the resistor that you just experimented with and assembles it in a network with one other resistor and places them inside a black box. He challenges you to tell him the configuration of the resistors inside the box. Being an industrious physics student you connect the leads of the black box to your power source, voltmeter (in parallel), and ammeter (in series) and take the following simultaneous measurements. Use the measurements to find the equivalent resistance of the arrangement.
V (volts) I (mA)
2.0 5.5
Part C: Now that you've answered his challenge, your lab partner asks you to give the resistance of the resistor that he added to the one you experimented with. Using the information you obtained in parts A and B, predict this value of the resistance of the second resistor.
Answer:
Kindly check explanation
Explanation:
Given the data:
Trial V (volts) I (mA)
1 1.00 7.2
2 2.10 14.0
3 3.10 20.7
4 4.00 27.2
5 4.90 32.2
Slope = Rise / Run
Rise = y2 - y1 = 32.2 - 7.2 = 25
Run = x2 - x1 = 4.9 - 1.0 = 3.9
Slope = 25 / 3.9 = 6.410
y = mx + c
The intercept, c
Take the point ( 1; 7.2)
Put x = 0
7.2 = 6.410(1) + C
7.2 - 6.410 = C
C = 0.79
We know that there is a relationship between work and mechanical energy change. Whenever work is done upon an object by an external force (or non-conservative force), there will be a change in the total mechanical energy of the object. If only internal forces are doing work then there is no change in the total amount of mechanical energy. The total mechanical energy is said to be conserved. Think of a real-life situation where we make use of this conservation of mechanical energy (where we can neglect external forces for the most part). Describe your example and speak to both the kinetic and potential energy of the motion.
Answer:
* roller skates and ice skates.
* roller coaster
Explanation:
One of the best examples for this situation is when we are skating, in the initial part we must create work with a force, it compensates to move, after this the external force stops working and we continue movements with kinetic energy, if there are some ramps, we can going up, where the kinetic energy is transformed into potential energy and when going down again it is transformed into kinetic energy. This is true for both roller skates and ice skates.
Another example is the roller coaster, in this case the motor creates work to increase the energy of the car by raising it, when it reaches the top the motor is disconnected, and all the movement is carried out with changes in kinetic and potential energy. In the upper part the energy is almost all potential, it only has the kinetic energy necessary to continue the movement and in the lower part it is all kinetic; At the end of the tour, the brakes are applied that bring about the non-conservative forces that decrease the mechanical energy, transforming it into heat.
In Spanish, count to 1000 in hundreds. (100, 200, 300, 400…1000) You will be graded on (a) pronunciation and (b) correct number vocabulary.
Find the polar angle (in radians with respect to +x-axis) of −3i + j.
Answer:
[tex]-18.43^{\circ}[/tex]
Explanation:
Let [tex]\theta[/tex] be the polar angle of −3i + j. We can find it using the formula as follows :
[tex]\tan\theta=\dfrac{y}{x}\\\\\tan\theta=\dfrac{1}{-3}\\\\\theta=\tan^{-1}(\dfrac{1}{-3})\\\\\theta=-18.43^{\circ}[/tex]
So, the required polar angle is [tex]-18.43^{\circ}[/tex].
Who was the first scientist to explore the moon with a telescope? A Isaac Newton B Johannes Kepler C Nicolaus Copernicus D Galileo Galilae
Answer:
D Galileo Galilae
Explanation:
It's now understood that English astronomer Thomas Harriot, (1560-1621) made the first recorded observations of the Moon through a telescope, a month before Galileo
Answer: Galileo Galilae
Explanation:
PLEASE HELP!!!! ITS URGENT!!!
Answer:
dude the answer is upright
The standing vertical jump is a good test of an athlete's strength and fitness. The athlete goes into a deep crouch, then extends theirlegs rapidly; when theirlegs are fully extended, theyleave the ground and rise to theirhighest height.It is the force of the ground on the athlete during the extension phase that accelerates the athlete to the final speed with which theyleave the ground.A good jumper can exert a force on the ground equal to twice theirweight. If thecrouch is 65 cm deep, how far off the ground do theyrise
Answer:
h = 1.3 m
Explanation:
For this exercise we can use the relationship between work and kinetic energy
W = Δx = K_f - K₀
in the exercise they indicate that the strength of the athlete is over twice his weight, therefore the ratio of the floor directed upwards has the same value
F = 2W
F = 2 mg
the displacement is x = 0.65 m, note that the direction of the force and the displacement is the same and the initial velocity is zero due to being crouched at rest, we substitute
F x = ½ m v² - 0
v² = 2 (2mg) x / m
v = [tex]\sqrt{4gx}[/tex]
let's calculate
v = [tex]\sqrt{ 4 \ 9.8 \ 0.65}[/tex]
v = 5.05 m / s
already in the air energy is conserved
starting point. Just when it comes off the ground
Em₀ = K = ½ m v²
final point. When is it at the highest part of the trajectory
Em_f = U = m g h
Em₀ = Em_f
½ m v² = m g h
h = ½ [tex]\frac{v^2}{g}[/tex]
let's calculate
h = ½ 5.05²/9.8
h = 1.3 m
When heat travels between two objects that are touching, it is moving by ________
radiation
convection
conduction
none of the above
When heat travels between two objects that are touching,
it is moving by conduction.
Fill in the blank. Consider the inverse square law: When light leaves a light bulb, it spreads out over more and more space as it goes. This makes the light thinner, with less and less light present the further from the light bulb we look. If we stand looking at a light bulb and see how bright it is, then move to be four times farther away from the light bulb, the light from the bulb will look ____________ less bright. Group of answer choices
Answer:
Explanation:
Intensity of light is inversely proportional to distance from source
I ∝ 1 /r² where I is intensity and r is distance from source . If I₁ and I₂ be intensity at distance r₁ and r₂ .
I₁ /I₂ = r₂² /r₁²
If r₂ = 4r₁ ( given )
I₁ / I₂ = (4r₁ )² / r₁²
= 16 r₁² / r₁²
I₁ / I₂ = 16
I₂ = I₁ / 16
So intensity will become 16 times less bright .
"16 times " is the answer .