Answer:
a) v = 32.8 m/s
b) v= 15.4 m/s
Explanation:
a)
Applying the definition of acceleration (assumed to be constant), we can write the following expression for the velocity v:[tex]v = v_{o} + a*t (1)[/tex]
where v₀ is the initial velocity and a is the acceleration, being t the
time elapsed.
In the case a) the acceleration and the velocity vectors have both the same direction (due north), so both have the same sign, which means that the car is speeding up.Replacing by the givens v₀ and t in (1), we get:[tex]v = 23.6 m/s + (1.30 m/s2 * 7.10 s) = 32. 8 m/s (2)[/tex]
b)
In this case, the acceleration vector and the velocity vector have opposite directions, so the car slows down, due to both vectors have opposite signs.Replacing by the givens in (1) and taking into account the signs, we get:[tex]v = 23.6 m/s + ((-1.15 m/s2) * 7.10 s)) = 15. 4 m/s (3)[/tex]
a car accelerate at 9 m/s squared. Assuming the car starts from rest how far will it travel in 10 seconds
Answer:
450m
Explanation:
[tex]s = ut + \frac{1}{2} a {t}^{2} \\ s = 0 + t + \frac{1}{2} a {t}^{2} \\ \frac{1}{2 } \times 9 \times {10}^{2} = 450m[/tex]
The properties of elements can be predicted by which of the following?
Answer:
1 Answer. The Periodic Table can predict the properties of new elements, because it organizes the elements according to their atomic numbers. Creating new elements is not a simple process. Scientists use a particle accelerator to smash light atoms into a thin metallic foil that contains heavier atoms.
Explanation:
What is my name?:
I am a god
I am a guardian of the sun
I am used to measure heat.
Answer:
Apllo?
Explanation:
Which heat related illness requires immediate medical attention
Answer:
Heat stroke
Explanation:
Heat Stroke is the most serious heat-related illness and requires immediate medical attention.
Answer:
Heat Stroke is the most serious heat-related illness and requires immediate medical attention. Symptoms include: confusion, fainting, seizures, very high body temperature and hot, dry skin or profuse sweating. CALL 911 if a coworker shows signs of heat stroke.
Explanation:
I HOPE THIS HELPS * pls mark me brainliest }
A 2.00 kg block on a horizontal floor is attached to a horizontal spring that is initially compressed 0.0300 m . The spring has force constant 815 N/m . The coefficient of kinetic friction between the floor and the block is μk=0.40. The block and spring are released from rest and the block slides along the floor.
Required:
What is the speed of the block when it has moved a distance of 0.0200 m from its initial position? (At this point the spring is compressed 0.0100 m.)
Answer:
v = 0.41 m/s
Explanation:
In this case, the change in the mechanical energy, is equal to the work done by the fricition force on the block.At any point, the total mechanical energy is the sum of the kinetic energy plus the elastic potential energy.So, we can write the following general equation, taking the initial and final values of the energies:[tex]\Delta K + \Delta U = W_{ffr} (1)[/tex]
Since the block and spring start at rest, the change in the kinetic energy is just the final kinetic energy value, Kf.⇒ Kf = 1/2*m*vf² (2)The change in the potential energy, can be written as follows:[tex]\Delta U = U_{f} - U_{o} = \frac{1}{2} * k * (x_{f} ^{2} - x_{0} ^{2} ) (3)[/tex]
where k = force constant = 815 N/m
xf = final displacement of the block = 0.01 m (taking as x=0 the position
for the spring at equilibrium)
x₀ = initial displacement of the block = 0.03 m
Regarding the work done by the force of friction, it can be written as follows:[tex]W_{ffr} = - \mu_{k}* F_{n} * \Delta x (4)[/tex]
where μk = coefficient of kinettic friction, Fn = normal force, and Δx =
horizontal displacement.
Since the surface is horizontal, and no acceleration is present in the vertical direction, the normal force must be equal and opposite to the force due to gravity, Fg:Fn = Fg= m*g (5)Replacing (5) in (4), and (3) and (4) in (1), and rearranging, we get:[tex]\frac{1}{2} * m* v^{2} = W_{ffr} - \Delta U = W_{ffr} - (U_{f} -U_{o}) (6)[/tex]
[tex]\frac{1}{2} * m* v^{2} = (- \mu_{k}* m*g* \Delta x) -\frac{1}{2} * k * (x_{f} ^{2} - x_{0} ^{2} ) (7)[/tex]
Replacing by the values of m, k, g, xf and x₀, in (7) and solving for v, we finally get:[tex]\frac{1}{2} * 2.00 kg* v^{2} = (-0.4*2.00 kg*9.8m/s2*0.02m) +( (\frac{1}{2} *815 N/m)* (0.03m)^{2} - (0.01m)^{2}) = -0.1568 J + 0.326 J (8)[/tex]
[tex]v =\sqrt{(0.326-0.1568} = 0.41 m/s (9)[/tex]The kinetic energy of an object of mass 3.5 kg is 112 J. Its speed is?
64 m/s
8.0 m/s
5.67 m/s
6.8 m/s
Which is not part of a DC motor?
Answer:
The correct answer to the question will be compass i.e compass is not a part of a DC motor. Various parts of a DC motor are coil of wire, armature, field magnets, brushes and commutator. The coil of wire plays a vital role in DC motor.
Explanation:
Define specific charge of an electron. Write its value.
Answer:
The specific charge is defined as a charge by mass ratio i.e e/m. The charge on an electron (e) = 1.602 X 10-19C. The mass of the electron (m) = 9.1×10−31Kg.
what is physical quantity
Answer:
physical quantity is a property of a material or system that can be qualified by measurement
[tex] \huge\mathfrak{ANSWER}[/tex]
the quantities by meals of which we describe the law of physics are known as physical quantities.
in order to measure a physical quantity we as you my certain magnitude of this quantity a standard and call its unit of that quantity to express the measurement of any physical quantity two thing must be mentioned.
the unit in which the quantity is measured.the numerical value which do not the magnitude of that quantity in term of the choosen unit.For Example -:
when we say that the length of a road is 20 m its mean that the unit of length is matter and the length of rod 20 time magnitude of metre.in other number the numerical value of physical quantities inversely proportional to its unit if N1 and N2 be the numerical value of a physical quantity into different unit u1 and u2 then[tex] \bold{ n_1 (u_1) = n_2(u_2)}[/tex]
hii Happy New year can you all please answer this
Answer:
truuuuuuuuuuuuueeeeeeeee
Which ray diagram demonstrates the phenomenon of absorption?
Answer:
B
Explanation:
The ray diagram demonstrated the phenomenon of absorption in B. Hence, option B is correct.
What is absorption?Absorption is the phenomenon of electromagnetic radiation taking up the energy of photons and it also transfers the electromagnetic energy to the internal energy of the absorber.
Absorption refers to the transfer of the energy of a wave to matter as the wave passes through it. The process in which the light waves get converted into energy. Absorption causes attenuation of the waves and the intensity decreases gradually when the light waves propagate through the medium.
From the given, the first diagram represents the light passes through the slit, it gets diffracted and forms alternate bright and dark fringes in the screen. The third diagram represents that the light ray strikes the surface it gets reflected and the path of light gets changed.
Thus, the absorption is the ray diagram given in the second image. Hence, option B is correct.
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Write a paragraph describing Newton's 2nd Law in YOUR OWN WORDS.
Explanation:
if u apply more force to an object, it accelerates at a higher rate
The greenhouse effect is
Egg A is dropped from a height of 1m onto the floor. Egg B is dropped from a height of 1m into a bucket of water. Which statement
correctly describes why Egg B does not break?
Answer:
maybe it's because a bucket of water has more density than egg B
Answer:
Egg B experiences less force over a shorter time
Explanation:
What is your average velocity after going 15 meters east followed by 20 meters
west in 10 seconds?
Answer:
0.5 m/s
Explanation:
Velocity = displacement/time taken
going 15 meters east and then 20 meters west gives a displacement of 5 meters.
Velocity v = 5/10
= 0.5 m/s
Which property of a solid measures how resistant the material is to deformation?
Answer: the answer would be b in k12
Explanation:
Estimate the weight of a 1000kg car that is accelerating at 3 m/s/s.
Answer:
W = 9800 N
Explanation:
Given that,
Mass of a car, m = 1000 kg
Acceleration of the car, a = 3 m/s²
We need to find the weight of the car. Weight of an object is given by the product of mass and acceleration due to gravity on the Earth.
W = mg
Put all the values,
W = 1000 kg × 9.8 m/s²
= 9800 N
So, the weight of the car is 9800 N.
Two resistors, A and B, are connected in parallel across of a 6V battery. The current through B is found to be 2.0 A. When the two resistors are connected in series to the 6V battery, a voltmeter connected across the resistor A measures a voltage of 4V. Find the resistances of A and B.
Answer:
Resistance of A is [tex]6\ \Omega[/tex] and B is [tex]3\ \Omega[/tex]
Explanation:
The voltage across both the resistances will be the same as they are connected in parallel.
V = Voltage = 6 V
[tex]I_B=2\ \text{A}[/tex]
Resistance is given by
[tex]R_B=\dfrac{V}{I_B}\\\Rightarrow R_B=\dfrac{6}{2}\\\Rightarrow R_B=3\ \Omega[/tex]
[tex]V_B=V_b-V_A\\\Rightarrow V_B=6-4\\\Rightarrow V_B=2\ \text{V}[/tex]
Series connection
[tex]V_A=4\ \text{V}[/tex]
The current is constant in series connection
[tex]I=\dfrac{V_B}{R_B}\\\Rightarrow I=\dfrac{2}{3}\ \text{A}[/tex]
[tex]R_A=\dfrac{V_A}{I}\\\Rightarrow R_A=\dfrac{4}{\dfrac{2}{3}}\\\Rightarrow R_A=6\ \Omega[/tex]
The resistance of A is [tex]6\ \Omega[/tex] and B is [tex]3\ \Omega[/tex].
The period of a pendulum is directly proportional to the mass of the bob.
true or false.
Answer:
false
Explanation:
i just took the test <3
The period of a pendulum is not directly proportional to the mass of the bob. The period of pendulum is independent of the mass of the bob. Thus, the given statement is false.
What is the period of pendulum?A simple pendulum is the one which consists of a small metal ball called as the bob or a mass which is suspended from a fixed point by a long piece of thread such that the bob is free to swing back and forth from its mean position under the influence of the gravity.
The time period of a simple pendulum is the time taken by it to complete one oscillation. The formula for the time period or period (T) of a simple pendulum is T = 2π (√L/g), where L is the length of the pendulum thread and g is the acceleration due to gravity.
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What may result when the energy that builds up at plate boundaries is released because the plates suddenly overcome the force of friction?
volcano
hot spot
earthquake
trench
All motion will eventually stop due to the "loss" of energy to___.
a) friction and thermal energy
b) gravity
c) kinetic energy
d) potential energy
You are assigned the design of a cylindrical, pressurized water tank for a future colony on Mars, where the acceleration due to gravity is 3.71 meters per second per second. The pressure at the surface of the water will be 150 KPa , and the depth of the water will be 14.4 m . The pressure of the air in the building outside the tank will be 88.0 KPa .
Find the net downward force on the tank's flat bottom, of area 2.15 m2 , exerted by the water and air inside the tank and the air outside the tank.
Answer: F = 6262.2 kN
Explanation: Pressure is defined as force per area. But pressure varies according to the depth of a fluid: in air, it decreases the higher the altitude, while in water, it increases the deeper you go.
So, at the bottom of the tank, besides the pressure of air inside the tank and air outside the tank, there is pressure of water due to its depth.
Pressure due to the depth is calculated as
[tex]P=h.\rho.g[/tex]
h is the depth in m
ρ is density of the fluid, in this case is water, so ρ = 997 kg/m³
g is acceleration due to gravity, which, in this case, is 3.71 m/s²
Then, pressure at the bottom of the tank due to variation in depth is
[tex]P=14.4(997)(3.71)[/tex]
P = 53263.73 Pa or 53.26 kPa
Assuming positive referential is downward, all pressures at the bottom point down, so total or resultant pressure is:
[tex]P_{r}=P_{1}+P_{2}+P_{3}[/tex]
[tex]P_{r}=150+88+53.26[/tex]
[tex]P_{r}=[/tex] 291.26 kPa
At last, pressure is force per area:
[tex]P=\frac{F}{A}[/tex]
[tex]F=P.A[/tex]
[tex]F_{r}=P_{r}.A[/tex]
[tex]F_{r}=291.26.10^{3}(2.15)[/tex]
[tex]F_{r}=[/tex] 626209 N or 626.2 kN
At the cylindrical tank's flat bottom, net force has magnitude 626.2 kN.
Which property of a solid measures how resistant the material is to deformation?
A. Elasticity
B. Hardness
C. Plasticity
D. resilience
Answer: the answer is a
Explanation:
58) Two balls, A and B are simultaneously projected from the top
of a building at 10 mis upwards & 20 m/s downwards respectively. Find
out the separation btwn them 3 sec after projection.
Answer:
90 m
Explanation:
For ball A::
The equation of a ball moving upwards is given by the formula:
s = ut - (1/2)gt²
where u is the initial velocity, t is the time covered, g is the acceleration due to gravity = 10 m/s² and s is the distance travelled.
Given that:
u = 10 m/s, t = 3 sec, g = 10 m/s², hence:
s = (10 * 3) - (1/2) * 10 * 3²
s = 30 - 45
s = -15 m
The negative sign means the object travels in the opposite direction. Hence s = 15 m
For ball B::
The equation of a ball falling downwards is given by the formula:
s = ut + (1/2)gt²
Given that:
u = 10 m/s, t = 3 sec, g = 10 m/s², hence:
s = (10 * 3) + (1/2) * 10 * 3²
s = 30 + 45
s = 75 m
Hence the separation between the two balls after 3 sec of projection = 15 m + 75 m = 90 m
What are two ways electromagnetic waves are used in a home computer scanner?
A.
An image is produced when a silicon chip releases electrons by the photoelectric effect.
B.
Visible light is reflected off an object and then captured by a charge-coupled device.
C.
X-rays shine on objects, and the rays either pass through or are absorbed by the objects.
D.
Red light shines on a black-and-white object, and light is reflected according to the pattern of black and white.
Two ways electromagnetic waves are used in a home computer scanner are:
An image is produced when a silicon chip releases electrons by the photoelectric effect.Visible light is reflected off an object and then captured by a charge-coupled device.What is electromagnetic wave?In terms of science, electromagnetic radiation (EMR) is made up of electromagnetic (EM) field waves that travel over space while carrying electromagnetic radiant energy. It consists of X-rays, gamma rays, microwaves, infrared, visible light, ultraviolet, and radio waves. These waves are all a component of the electromagnetic spectrum.
Electromagnetic waves, which are synchronised oscillations of the electric and magnetic fields, are the traditional form of electromagnetic radiation. The electromagnetic spectrum is created at various wavelengths depending on the oscillation frequency. Electromagnetic waves move at the speed of light in a vacuum.
Hence, option (A) and (B) are correct.
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For each of the situations described below, the object considered is undergoing some changes. Among the possible changes you should consider are:
(Q) The object is absorbing or giving off heat.
(T) The object's temperature is changing.
(E) The object's thermal energy is changing.
(W) The object is doing mechanical work or having work done on it.
(C) The objects chemical energy is changing.
For each of the two situations, identify which of the five changes is taking place, indicating the applicable letters Q T U W C (or none) as appropriate while providing your reasoning.
a. An ice cube sits in the open air and is melting.
b. A cylinder with a piston on top contains a compressed gas and is sitting on a thermal reservoir (a large iron block that can provide or take thermal energy as the system needs). After everything has come to thermal equilibrium, the piston is moved upward somewhat (very slowly). The object to be considered is the gas in the cylinder.
Answer: a. (Q), (T), (E)
b. (Q), (T), (E), (W)
Explanation: Thermal Energy and Temperature are closely related: when the temperature rises causing atoms or molecules to move, thermal energy is produced. Thermal energy is the energy within the system.
Mechanical Work is the amount of energy transferred due to an applied force.
Chemical Energy is the energy contained in the bonds of chemical structures of the molecules released when a chemical reaction happens.
Given the explanations, let's analyse the situations:
a. For an ice cube to be melting, it has to be absorbing heat, which means its thermal energy is changing and, consequently, so does its temperature;
b. First, the gas inside the cylinder reaches a thermal equilibrium, which means its thermal energy and temperature changed. Since there were exchange of heat to reach the equilibrium, the gas absorbed or gave off heat. After the equilibrium, when the piston starts to be moved, the energy of the pressure is transferred to the gas, so mechanical work had been done.
What happens to the molecules of a substance when it changes phase?
When it comes to phase shifts or phase change the greater the intermolecular interactions are the closer the molecules are to one another.
What is phase change?A phase change occurs when matter transitions from one state to another (solid, liquid, gas, plasma). When enough energy is provided to the system (or when a significant quantity is removed), as well as when the pressure on the system is adjusted, these changes occur.Any two phases of matter can undergo phase transitions.All phase shifts are accompanied by an energy shift.Isothermal phase shifts occur in all cases.Temperature changes can cause substances to change phase often. Most substances are solid at low temperatures; as the temperature rises, they become liquid; and at even higher temperatures, they become gaseous.To Know more about Phase change here
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Various radial points on a rotating Ferris wheel have: I. different linear velocities II. different angular velocities III. equal linear velocities IV. equal angular velocities
Answer:
I) True, II) False, III) False, IV) True
Explanation:
In this exercise, it is asked to answer different statements, for this we will use the relationship between angular and linear velocity
v = w r
let's review the claims
I) True. From the initial equation we see that the linear velocity depends on the radius
II) False. All points rotate with the same angular velocity
III) False. Linear velocity changes with radius
IV) True. The angular velocity of all points is the same
At various radial points on a rotating Ferris wheel have, different linear velocity (True), different angular velocity (false), equal linear velocity (false) and equal angular velocity (True).
The angular velocity of a rotating Ferris is calculated as follows;
[tex]\omega = \frac{v}{r} = 2\pi N[/tex]
The linear velocity of a rotating Ferris is calculated as follows;
v = ωr
where;
v is the linear velocityr is the radius of the Ferrisω is the angular velocityThe linear velocity increases with increase in radius.
Thus, we can conclude that, at various radial points on a rotating Ferris wheel have;
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Which of the following is NOT an argument for showing that the Earth must be round: a. during an eclipse of the Moon, the shadow of the Earth is always seen to be round b. when ships travel a large distance away, we see their hulls disappear first and their masts disappear last c. the height of the North Star changes as we travel to different latitudes d. photographs of the Earth from space always show a round body e. the Sun is seen blocking different constellations in the course of a year Submit Your Answer
Answer: The correct option is option E (the Sun is seen blocking different constellations in the course of a year.
Explanation:
The earth, which is one of the planets of the solar system that supports life, is shperical in shape. The spherical ( round) shape of the earth is marked by the intervening highlands and oceans on its surface.
Evidence to show that the earth is shperical are:
--> The Lunar eclipse: During an eclipse of the Moon, the shadow of the Earth is always seen to be round.
--> Ships Visibility: When ships travel a large distance away, we see their hulls disappear first and their masts disappear last.
-->Altitude of Polaris (North Star): The height of the North Star changes as we travel to different latitudes. That is ,increases as you move toward the North pole, or decreases as you move toward the equator.
--> Aerial photographs: Photographs of the Earth from space always show a round body.
The statement that doesn't prove that the earth is spherical in shape is (the Sun is seen blocking different constellations in the course of a year). The sun is seen in front of stars blocking different constellation in a year because the earth orbits round the sun in a year and not that it is shperical in shape.
Chirag, a champion weightlifter, raises 259 kg of weights a distance of 2.40 m. How much work is done by Brutus lifting the weights?
622 J
6090 J
2540 J
0 J
How much work is done by Chirag holding the weights above his head?
622 J
6090 J
2540 J
0 J
1.
6090 J
2.
622 J
I bet so~