Answer:
v = 0.5 m/s.
Explanation:
Total distance, d = 20 m + 20 m = 40 m
Total time taken, t = 30 s + 50 s = 80 s
The average speed of an object is the total distance divided by time taken. So,
[tex]v=\dfrac{40}{80}\\\\=0.5\ m/s[/tex]
So, the average speed of the object is 0.5 m/s.
A gazelle is running at a constant speed of 19.3 m/s toward a motionless hidden cheetah. At the instant the gazelle passes the cheetah, the cheetah accelerates at a rate of 7.1 m/s/s in pursuit of the gazelle. The gazelle maintains its constant speed. By the time the cheetah reaches a speed of 19.3 m/s to match the gazelle, how far apart are the two animals in units of m
Answer:
the animals are 26.2 meters apart.
Explanation:
Let's define t = 0s as the moment when the cheetah starts accelerating.
The gazelle moves with constant velocity, thus, it is not accelerating, then the acceleration of the gazelle is:
a₁(t) = 0m/s^2
where I will use the subscript "1" to refer to the gazelle and "2" to refer to the cheetah.
for the velocity of the gazelle we just integrate over time to get:
v₁(t) = V0
where V0 is the initial speed of the gazelle, which we know is 19.3 m/s
v₁(t) = 19.3 m/s
To get the position of the gazelle we integrate again:
p₁(t) = ( 19.3 m/s)*t + P0
where P0 is the position of the gazelle at t = 0s, let's define P0 = 0m
p₁(t) = ( 19.3 m/s)*t
The equations that describe the motion of the gazelle are:
a₁(t) = 0m/s^2
v₁(t) = 19.3 m/s
p₁(t) = ( 19.3 m/s)*t
Now let's do the same for the cheetah.
We know that its acceleration is 7.1 m/s^2
then:
a₂(t) = 7.1 m/s^2
for the velocity of the cheetah we integrate:
v₂(t) = (7.1 m/s^2)*t + V0
where v0 is the initial velocity of the cheetah, which we know its zero.
v₂(t) = (7.1 m/s^2)*t
Finally, for the position equation we integrate again, and remember that we have defined the initial position for the gazelle as zero, then the same happens for the cheetah.
p₂(t) = (1/2)*(7.1 m/s^2)*t^2
The equations for the cheetah are:
a₂(t) = 7.1 m/s^2
v₂(t) = (7.1 m/s^2)*t
p₂(t) = (1/2)*(7.1 m/s^2)*t^2
Now, we want to find the distance between both animals when the speed of the cheetah is 19.3 m/s, then first we need to solve:
v₂(t) = (7.1 m/s^2)*t = 19.3 m/s
t = (19.3 m/s)/(7.1 m/s^2) = 2.72s
Now, to find the distance between the two animals, we just compute the difference between the position equations for t = 2.72s
Distance = p₁(2.72s) - p₂(2.72s)
= ( 19.3 m/s)*2.72s - (1/2)*(7.1 m/s^2)*(2.72s)^2
= 26.2 m
So the animals are 26.2 meters apart.
What is the energy stored in food?
Hey there!
The energy that is stored in food is called CHEMICAL ENERGY
So, when humans/people eat foods their bodies transfigure the energy that is stored which is known as the calories.
Whereas the chains (bonds) in the middle of the atoms in the food humans eat that break up the check mal reactions that has been taken into place and newer compounds will be created. Each food that you eat stores unlikeable amounts of energy
Answer: Chemical energy
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)
Ftension
120 N
10 kg
Fg
What is the net force on the box?
O 22 Newtons upward
120 Newtons upward
O 98 Newtons downward
O O Newtons
Answer:
120N Hacia arriba
A wave with a frequency of 60 hertz would generate 60 wave crests every
Answer:
A wave with a frequency of 60 hertz will have 60 successive wave crests occurring every second
Explanation:
A crest is the highest point the medium rises to in a wave. That means that the crest is a point on the wave where the displacement is at a maximum.
Frequency is the number of oscillations of a wave in one second. Hence, frequency of a wave is the number of successive crests occurring in a second.
Therefore a wave with a frequency of 60 hertz will have 60 successive wave crests occurring every second.
Which of the following would NOT produce a current? A. Moving a bar magnet inside a coil of wire O B. Moving a bar magnet toward a straight wire C. Moving a straight wire toward a bar magnet O D. Placing a bar magnet next to a wire.
Answer:
c
Explanation:
Answer:C
Explanation:
What is the gain in gravitational potential energy of a body of weight 2000N as it rises from a height of 20m to a height of 25 m above the Earth's surface
Answer:
Explanation:
GPE =weight * height
= 2000*(25-20)
= 10000 J
Gain of Gravitation Potential energy = 10,000 J
What is Gravitation Potential Energy ?
It is the energy acquired by an object due to a change in its position when it is present in a gravitational field .
To calculate gravitational potential energy at height h , formula used is = m g h where m = mass of the body
g = acceleration due to gravity
h = height from the ground
Gain of Gravitation Potential energy = mg(h2 - h1 ) h2 = final height
h1 = initial height
= 2000 (25 -20) (since , mg =weight)
Gain of Gravitation Potential energy = 10,000 J
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4.Upthrust doesnt depend on the following Physical quantity?
volume of body
density of body
mass of body
acceleration due to gravity
Answer:
C: Mass of body
Explanation:
Upthrust is defined as the upward force that a liquid will exert on a body floating atop it.
Now, Formula for upthrust is;
Upthrust = density of liquid × volume of the body × acceleration due to gravity.
From the formula, we can see that upthrust depends on density, volume and acceleration due to gravity.
Thus, looking at the options, the one that doesn't apply is mass of body.
DL: Activity 2.3 Resistance Complete the questions based on the Resistance presentation. a. All resistors ___________ or _____________ the flow of electrons. b. As resistance __________________ current _______________________
DL: Activity 2.3 Resistance
Complete the questions based on the Resistance presentation.
a. All resistors ___________ or _____________ the flow of electrons.
b. As resistance __________________ current _______________________
Answer:a) limits or opposes
b) increases, decreases
Explanation:Resistors are electrical devices used to resist, limit, oppose or hinder the flow of electrons in a circuit. This resistance causes a reduction in current and an increase in voltage in the circuit. In order words, as resistance increases, the current decreases and voltage increases.
This was further stated by Ohm's law that states that as long as the resistance in a wire/conductor remains constant, the voltage across it is directly proportional to the current flowing through a conductor. i.e
V = IR
Where;
R = constant called resistance
I = current flowing through the wire
V = voltage across the wire
Genes are arranged on a twisted strands called.
Light with some unknown wavelength is incident on a piece of copper. The most energetic electrons emitted from the copper have 2.7 eV of kinetic energy. If the copper is replaced with a piece of sodium, what will be the maximum possible kinetic energy K of the electrons emitted from this new surface
This question is in complete, the missing table is uploaded along this answer.
Answer:
the maximum possible kinetic energy K of the electrons emitted from this new surface is 4.9 eV
Explanation:
Given the data in the question;
copper K = 2.7 eV
If the copper is replaced with a piece of sodium ( Na )
the maximum possible kinetic energy K of the electrons emitted from this new surface = ?
we know that;
Kinetic energy of emitted electrons can be written as;
K = hv - hv₀
where v is frequency, h is Plank's constant, and hv₀ is work function of metal
so lets make hv the subject of formula;
hv = K + hv₀
from the table below, work function of copper is 4.5 eV
so we substitute
hv = 2.7 eV + 4.5 eV
hv = 7.2 eV
Now, If the copper is replaced with a piece of sodium ( Na )
we have;
K = hv - hv₀
from the table below, work function of Sodium is 2.3 eV
so we substitute
K = 7.2 eV - 2.3 eV
K = 4.9 eV
Therefore, the maximum possible kinetic energy K of the electrons emitted from this new surface is 4.9 eV
Calculate the pressure exerted on the floor when an
elephant who weighs 2400N stands on one foot which has
an area of 4m²?
P = F / A
P = 2400 / 4
P = 24 × 100 / 4
P = 6 × 100
P = 600 N/m^2
Adverb of place:
1
Adverb of time:
2
Adverb of place:
3
Adverb of time:
4
Adverb of place:
5
Answer:
1 there,here, somewhere,nowhere,everywhere
2.now,yesterday,then,
An astronaut weighing 248 lbs on Earth is on a mission to the Moon and Mars. (a) What would he weigh in newtons when he is on the Moon
Answer:
[tex]W_m=183.495N[/tex]
Explanation:
From the question we are told that:
Weight [tex]W=248Ibs[/tex]
Mass of Weight [tex]m= 248*0.453[/tex]
[tex]m=112.344kg[/tex]
Generally the acceleration due to gravity on the Moon is one-sixth that on Earth.
Therefore
The equation for Weight on Moon is given as
[tex]W_m=m*g/6[/tex]
[tex]W_m=122.344*\frac{9.8}{6}[/tex]
[tex]W_m=183.495N[/tex]
Answer:
F ’= 40.9 lb
Explanation:
The weight of a body is the attraction of the Earth on the body
F = [tex]G \frac{m M_e}{R_e^2}[/tex]
F = mg
m = F / g
m = 248/32
m = 7.75 slug
The weight of the body on the moon is the attraction of the body for the satellite
F ’= [tex]G \frac{mM}{R^2}[/tex]
from the tables the mass and radius of the moon are M = 7.34 10²² kg and R = 1.74 10⁶ m
let's reduce the mass to the SI system
m = 7.75 slug (14.59 kg / 1 slug) = 113 kg
F ’= 6.67 10⁻¹¹ 113 7.34 10²² / (1.74 10⁶) ²
F ’= 1.82 10² N
F ’= 1.82 10² N (0.2248 lb / 1 N)
F ’= 40.9 lb
A 0.200 m wire is moved parallel to a 0.500 T
magnetic field at a speed of 1.50 m/s. What emf is
induced across the ends of the wire?
Answer:
The required emf moved across the wire is zero
Explanation:
For a moving charge particle, the magnetic force can be determined by using the formula;
[tex]\varepsilon = Bvlsin \theta[/tex]
since the wire moves in parallel, the angle [tex]\theta[/tex] between magnetic field and velocity = 0°
B = 0.500 T
v = 1.50 m/s
l = 0.200 m
∴
[tex]\varepsilon = (0.500 \ T )(1.50 \ m/s) \times (0.200 \ m)\times sin (0)[/tex]
[tex]\varepsilon = 0.15\times sin (0)[/tex]
[tex]\varepsilon = 0[/tex]
A system consists of a gas in an enclosed cylinder attached to a movable piston. The system is initially at 63 L and then is compressed to 31 liters. Determine the sign of work. Will it be a negative or positive
Answer:
The sign of work will be negative.
Explanation:
The work of the system is given by:
[tex] W = _{V_{i}}^{V_{f}}\int pdV = p(V_{f} - V_{i}) [/tex]
Where:
[tex]V_{f}[/tex]: is the final volume = 31 L
[tex]V_{i}[/tex]: is the initial volume = 63 L
p: is the pressure
Even though we do not have the pressure value, by knowing the values of the initial and final volume we can predict the sign of work.
[tex] W = p(V_{f} - V_{i}) = p(31 L - 63 L) = -32p [/tex]
Therefore, the sign of work will be negative.
I hope it helps you!
With the frequency set at the mid-point of the slider and the amplitude set at the mid-point of the slider, approximately how many grid marks is the wavelength of the wave (use the pause button and step button as you need to in order to get a good measure, and round to the nearest whole grid mark)?
If the amplitude is increased the wavelength:___________.
a. decreases
b. stays the same
c. increases
Answer:
correct answer is b
Explanation:
The frequency of a wave depends on the properties of medium density and the elasticity properties change the amplitude depends on the energy carried by the wave, that is, the amplitude is proportional to the height of the wave (oscillation).
Consequently the amplitude of independent of the frequency because it depends on different factors.
Therefore when changing the amplitude the wavelength remains constant
the correct answer is b
Which of the following is an expression of Newton's second law? A. The acceleration of an object is determined by its mass and the net force acting on it. O O B. Objects at rest tend to stay at rest and objects in motion tend to stay in motion unless acted on by an unbalanced force. C. Objects at rest tend to stay at rest, and objects in motion tend to slow down until they come to rest. D. Every force is paired with an equal and opposite force.
Answer: A. The acceleration of an object is determined by its mass and the net force acting on it.
Explanation:
Newton's second law of motion explains that the acceleration of an object will depend on two vital variables which are the mass of the object and the net force that's acting on it.
It should be noted that the acceleration of the object directly depend on the net force while it depends inversely on the mass. Therefore, when the force that's acting on such object is increased, then the acceleration will increase as well. On the other hand, when there is an increase in mass, there'll be a reduction in the acceleration.
6) The temperature of 10 kg of a substance rises by 55°C when heated. Calculate the
temperature rise when 22 kg of the substance is heated with the same quantity of heat.
Answer:
121
Explanation:
What is the vibrating source that creates sound waves?
Answer:
Sound is produced when an object vibrates, creating a pressure wave. This pressure wave causes particles in the surrounding medium (air, water, or solid) to have vibrational motion. As the particles vibrate, they move nearby particles, transmitting the sound further through the medium.
The strength of a magnetic field around a wire carrying a current of 20 A is 0.004 T. What is the strength of the
magnetic field if the current is changed to 40 A?
A 0.002 T
B 0.004 T
C 0.006 T
D 0.008 T
Answer:
D) 0.008
Explanation:
I just did it on Edg22 and I got it correct :D (Picture above)
Option D) 0.008T is the correct answer.
Hence, if the current is increased to the given value, the strength of the magnetic field around the wire carrying the current increases to 0.008T
Given the data in the question;
First scenario
Strength of magnetic field; [tex]B = 0.004T[/tex]Current; [tex]I = 20A[/tex]Second scenario
Strength of magnetic field; [tex]B' =\ ?[/tex]Current; [tex]I' = 40A[/tex]Magnetic FieldMagnetic field is a vector field or region around a magnet or electric charge upon which magnetic force is exerted.
To determine the strength of the magnetic field if the current is changed, we equate the two scenario.
[tex]\frac{B}{I} = \frac{B'}{I'}[/tex]
We substitute our given values into the expression
[tex]\frac{0.004T}{20A} = \frac{B'}{40A}\\ \\ B' * 20A = 0.004T * 40A\\\\B' = \frac{0.004T * 40A}{20A} \\\\B' = \frac{0.004T * 40}{20}\\ \\B' = \frac{0.16T}{20}\\ \\B' = 0.008T[/tex]
Option D) 0.008T is the correct answer.
Hence, if the current is increased to the given value, the strength of the magnetic field around the wire carrying the current increases to 0.008T
Learn more about magnetic field here: https://brainly.com/question/15695203
During a long jump, an Olympic champion's center of mass rose about 1.2 m from the launch point to the top of the arc. 1) What minimum speed did he need at launch if he was traveling at 6.8 m/s at the top of the arc
Answer: Minimum speed needed by the Olympic champion at launch if he was traveling at 6.8 m/s at the top of the arc is 11.65 m/s.
Explanation:
Velocity is only in horizontal direction at the top most point which is similar to the velocity in the horizontal direction at the time of launch.
Now, according to the law of conservation of energy the formula used is as follows.
[tex]mgh = \frac{1}{2} mv^{2}_{y}\\v_{y} = \sqrt{2gh}\\= \sqrt{2 \times 9.8 m/s^{2} \times 1.2}\\= 4.85 m/s[/tex]
As speed at which the person is travelling was 6.8 m/s. Hence, the initial velocity will be calculated as follows.
[tex]v = \sqrt{v^{2}_{x} + v^{2}_{y}}\\= \sqrt{(6.8)^{2} + (4.85 m/s)^{2}}\\= 11.65 m/s[/tex]
Thus, we can conclude that minimum speed needed by the Olympic champion at launch if he was traveling at 6.8 m/s at the top of the arc is 11.65 m/s.
a typical cmall flashlight contains two batteries each having na emf of 2.0 v connected in series with a bulb havin ga resistance of 16 ohms if the internal resistance of the batteries is negligible what power is delivered to the ublb
Answer:
P = 0.25 W
Explanation:
Given that,
The emf of the battry, E = 2 V
The resistance of a bulb, R = 16 ohms
We need to find the power delivered to the bulb. We know that, the formula for the power delivered is given by :
[tex]P=\dfrac{V^2}{R}\\\\P=\dfrac{2^2}{16}\\\\=0.25\ W[/tex]
So, 0.25 W power is delivered to the bulb.
Which element is the biggest contributor to Climate Change?
Answer:
carbon dioxide (CO2)
Explanation:
the burning or combustion of these fossil fuels creates gases that are released into the atmosphere. Of these gases, carbon dioxide (CO2) is the most common and is the gas most responsible for exacerbating the green- house effect that is changing global climate patterns.
An electric eel develops a potential difference of 470 V , driving a current of 0.85 A for a 1.0 ms pulse. Part A Find the power of this pulse.
Answer:
399.5 Watts.
Explanation:
From the question given above, the following data were obtained:
Potential difference (V) = 470 V
Current (I) = 0.85 A
Time (t) = 1 ms
Power (P) =?
Electrical power is defined by the following equation:
Power (P) = potential difference (V) × current (I)
P = IV
Using the above formula, the power can be obtained as follow:
Potential difference (V) = 470 V
Current (I) = 0.85 A
Power (P) =?
P = IV
P = 470 × 0.85
P = 399.5 Watts
Therefore, the power is 399.5 Watts.
What is the average speed (in km/h) of Zhana, who runs to the store that is 4.0 km away in 30.0 minutes?
0.13 km/ h
8.0 km/h
2.0 km/h
Answer:
2.0km/h.
Explanation:
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Preocupada com o aumento da tarifa na conta de luz, uma pessoa resolve economizar diminuindo o tempo de banho de 20 para 15 minutos. Seu chuveiro possui as seguintes especificações: 4200 W e 220V. Sabendo que o kWh custa R$0,30, a economia feita em 10 dias foi de aproximadamente
what is parallelogram law of vector addition ???
Answer:
According to the parallelogram law of vector addition if two vectors act along two adjacent sides of a parallelogram(having magnitude equal to the length of the sides) both pointing away from the common vertex, then the resultant is represented by the diagonal of the parallelogram passing through the same common vertex
Explanation:
Does every magnet have a north and south pole?
yes
no
a given mass of an ideal gas law occupies a volume V of a temperature T under a pleasure p, if the pressure is increased to 2 p and temperature 1/2 T what is the percentage change in the volume of the gas
Answer:
75%
Explanation:
We'll begin by calculating the final volume of the gas. This can be obtained as follow:
Initial volume (V₁) = V
Initial temperature (T₁) = T
Initial pressure (P₁) = P
Final pressure (P₂) = 2P
Final temperature (T₂) = ½T
Final volume (V₂) =?
P₁V₁/T₁ = P₂V₂/T₂
PV/T = 2P × V₂ / ½T
Cross multiply
T × 2P × V₂ = PV × ½T
T × 2P × V₂ = PV × ½T
Divide both side by T × 2P
V₂ = (PV × ½T) / T × 2P
V₂ = ¼V
Next, we shall determine the absolute change in the volume of the gas. This can be obtained as follow:
Initial volume (V₁) = V
Final volume (V₂) = ¼V
Absolute change in volume |ΔV| =?
|ΔV| = |V₂ – V₁|
|ΔV| = |¼V – V|
|ΔV| = |0.25V – V|
|ΔV| = 0.75V
Finally, we shall determine percentage change in the volume of the gas. This can be obtained as follow:
Initial volume (V₁) = V
Absolute change in volume |ΔV| = 0.75V
Percentage change =?
Percentage change = |ΔV| / V × 100
Percentage change = 0.75V / V × 100
Percentage change = 0.75 × 100
Percentage change = 75%
Thus, the percentage change in the volume of the gas is 75%
Subtract the following numbers, using scientific notation and the correct number of significant digits.
6.94 × 103 mm - 4.5 × 102 mm = _____.
2.4 × 103 mm
2.44 × 102mm
6.49 × 103 mm
6.5 × 103 mm
Answer:
The correct answer is - 6.49 × 10^3 mm.
Explanation:
The correct scientific notation of the given subtraction problem is:
6.94 × 10^3 mm - 4.5 × 10^2 mm = _____.
The correct number of significant digits is
a. 6.94 × 10^3 mm = 3
b. 4.5 × 10^2 mm = 2
So subtracting the 6.94 × 10^3 mm - 4.5 × 10^2 mm
= 6940 - 450
= 6.49× 10^3 mm.
Answer:
6.5x 10^3 mm
Explanation: