Một vật có khối lượng 2 kg rơi tự do xuống đất trong khoảng thời gian 0,5 s. Độ biến thiên động lượng của vật trong khoảng thời gian đó là bao nhiêu ? Cho g = 10 m/s2.

Answers

Answer 1

Answer: The change in momentum is +20 kg.m/s

Explanation:

To calculate the final velocity of object, we use the first equation of motion:

[tex]v=u+at[/tex]

where,

v = final velocity

u = initial velocity = 0 m/s

a = acceleration = [tex]10m/s^2[/tex]

t = time = 0.5 s

Putting values in above equation, we get:

[tex]v=0+(10\times 0.5)\\\\v=5m/s[/tex]

Momentum is defined as the product of the mass and velocity of an object. It is given by the equation:

[tex]p=mv[/tex]

where,

p = momentum

m = mass of object = 2 kg

Let the upward velocity be positive and the downward velocity be negative

When the object is dropped, the velocity is downward

v = -5m/s

Initial momentum = [tex]2kg\times (-5m/s)=-10kg.m/s[/tex]

When the object is bounced back, the velocity is upward

v = +5m/s

Final momentum = [tex]2kg\times (+5m/s)=10kg.m/s[/tex]

Change in momentum = Final - Inital

Change in momentum = [10 - (-10)] = +20 kg.m/s

Hence, the change in momentum is +20 kg.m/s


Related Questions

List two applications of an echo? ​

Answers

Answer:

I think the echo sounds do not depend on the direction of the sound and sound the same as the original sound

Explanation:

An echo is defined as a sound that is produced when a sound wave is reflected back from any hard surface and repeated.

Two major application of echo include:

- Bats, fisherman, and dolphins use echoes to detect or identify any object /obstruction.

- Echo is widely used in medical science applications for imaging of human organs such as echocardiography and ultrasound.

I hope this help you!:)

inertia is a force whuch keeps stationary object at rest and moving objects in motion is it trur?

Answers

Answer:

True

Explanation:

Inertia is the resistance of any physical object to any change in its velocity. This includes changes to the object's speed, or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight line at a constant speed, when no forces act upon them

Answer:

True po sagot sabihin mo kong mali

pleaase help me i don't know this !!!

Answers

Answer:

coefficient=1.09N/m×g

coefficient=1.09N/0.413g×10m/s square

coefficient=1.09N/4.13N

coefficent=0.263

f= uK

here f is force, u is cofficient of friction , k is normal force

k = mg

f = umg

1.09 = u × 0.41 × 10

u = 1.09 ÷ 4.1

u = 0.26

In what way is Height related to Potential Energy?​

Answers

Explanation:

Lets say you have a ball in your hand, you raise your hand to just above your head. Now, when you did that you created potential energy that is ready to be released. you drop the ball and the ball bounces a few times off the ground. Now lets say you got a ladder and doubled the ball's height doubling the energy now stored in the ball, when you drop it the ball should bounce much higher after hitting the ground as a result of more energy being released.

Hope this helped.

''Hydropower is also the product of solar energy''. clarify this statement​

Answers

Answer:

well, hydropower is using fast-running water as a source of power to power machines or produce electricity, and using water can help make the earth a little cleaner, just like solar energy (energy from the sun). instead of using things like coal, oil, gas which is bad for the earth

Explanation:

Object A has twice the mass of object B. Both objects are moving at the same speed. Which accurately describes how inertia relates to Newton’s second law of motion in this example? Object A has twice the mass of object B. Both objects are moving at the same speed.

A. Object A requires twice the force to stop as Object B.

B. Object A requires one-and-a-half times the force to stop as Object B.

C. Object A requires four times the force to stop as Object B.

Answers

Answer:

A. Object A requires twice the force to stop as Object B.

Explanation:

Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.

Newton's Second Law of Motion states that the acceleration of a physical object is directly proportional to the net force acting on the physical object and inversely proportional to its mass.

Mathematically, it is given by the formula;

[tex] Acceleration = \frac {Net \; force}{mass} [/tex]

Let's assume the following values;

Mass of object B = 10 kg

Mass of object A = 2 * B = 2 * 10 = 20 kg

Acceleration = 5 m/s²

I. To find the force for B;

[tex] Force = mass * acceleration [/tex]

[tex] Force = 10 * 5 [/tex]

Force B = 50 Newton

II. To find the force for A;

[tex] Force = mass * acceleration [/tex]

[tex] Force = 20 * 5 [/tex]

Force A = 100 Newton

From the calculation, we can deduce that Force A (100 N) is twice or double the value of Force B (50 N).

In conclusion, since object A has twice the mass of object B and both objects are moving at the same speed, object A would require twice the force to stop as Object B.

Which instrument changes kinetic energy into electrical energy?

electric motor

hair drier

electric bell

dynamo​

Answers

Answer:

Dynamo

Explanation:

As we all know, there are dynamos in bicycles. When we paddle the cycle, the wheels of the cycle rotates by generating kinetic energy. When the wheels rotate, the dynamo starts to rotate. This makes the motor inside the dynamo rotates and generate electrical energy.

This is the last 2 questions i need! It’s due in 10 minutes please help!! I will mark brainliest asap

Answers

Answer:

I don't know 11 but in no. 10,

The ans is 3.66

Total distance = 10m+30m+15m = 55m

Total time = 5secs+7secs +3secs =15secs

Av speed = d/t =55/15 = 3.66 m/s

1. The algebraic letter 'dy' stands for

Answers

I think it’s the derivative of y

the ratio of the energy per second radiated by the filament of a lamp at 250k to that radiated at 2000k, assuming the filament is a blackbody radiator? The filament of a particular electric lamp can be considered as a 90%blackbody radiator. calculate the energy per second radiated when its temperature is 2000k if its surface area is 10∧-6 m²

Answers

Answer:

(a) [tex]\frac{P_{250k}}{P_{2000k}}=2.4\ x\ 10^{-4}[/tex]

(b) P =  0.816 Watt

Explanation:

(a)

The power radiated from a black body is given by Stefan Boltzman Law:

[tex]P = \sigma AT^4[/tex]

where,

P = Energy Radiated per Second = ?

σ = stefan boltzman constant = 5.67 x 10⁻⁸ W/m².K⁴

T = Absolute Temperature

So the ratio of power at 250 K to the power at 2000 K is given as:

[tex]\frac{P_{250k}}{P_{2000k}}=\frac{\sigma A(250)^4}{\sigma A(2000)^4}\\\\\frac{P_{250k}}{P_{2000k}}=2.4\ x\ 10^{-4}[/tex]

(b)

Now, for 90% radiator blackbody at 2000 K:

[tex]P = (0.9)(5.67\ x\ 10^{-8}\ W/m^2.K^4)(1\ x\ 10^{-6}\ m^2)(2000\ K)^4[/tex]

P =  0.816 Watt

Why is the time period of a charged particle in a uniform magnetic field independent of velocity??

Answers

Answer:

time period is independent of K.E of particle, it is inversely proportional to specific charge of the particle and it is independent of angle between velocity and magnetic field

The spring in the toy is compressed 0.070 meter by using a downward force of 12.0 newtons. Calculate the spring constant, in N/m, of the spring.

Answers

Answer:

The spring constant is 171.43 N/m.

Explanation:

compression in spring, x = 0.07 m

force, F = 12 N

Let the spring constant is K.

Use the formula of the restoring force of the spring

F = K x

12 = K (0.07)

K = 171.43 N/m  

a student drops a ball off the top of building and records that the ball takes 3.32s to reach the ground (g=9.8 m/s^2). what is the ball's speed just before hitting the ground?​

Answers

Answer:

Explanation:

Use the one-dimensional equation for motion

v = v₀ + at and filling in,

v = 0 + (-9.8)(3.32) so

v = -33 m/s (negative because it is going downwards and upwards is positive).

How long will it take the cart to to travel 2.8m, starting from rest?

Answers

Answer:

0.748seconds

Explanation:

s = 1/2 *g*t^2

2.8 = 1/2 * 10* t^2

5.6 = 10 * t^2

0.56 = t^2

t = √0.56

t = 0.7483seconds

A train starts from rest and leaves Greenburg station with an acceleration of 1.20 meters per second2. How long does it take the train to travel a distance of 500 meters?

Answers

Answer:

Time, t = 28.87 seconds

Explanation:

Given the following data;

Acceleration = 1.20 m/s²

Distance = 500 meters

Initial velocity = 0 m/s

To find the time to cover the distance, we would use the second equation of motion;

[tex] S = ut + \frac {1}{2}at^{2}[/tex]

Where;

S represents the displacement or height measured in meters.

u represents the initial velocity measured in meters per seconds.

t represents the time measured in seconds.

a represents acceleration measured in meters per seconds square.

Substituting into the equation, we have;

[tex] 500 = 0*t + \frac {1}{2}*(1.2)*t^{2}[/tex]

[tex] 500 = 0 + 0.6*t^{2} [/tex]

[tex] 500 = 0.6t^{2} [/tex]

[tex] t^{2} = \frac {500}{0.6} [/tex]

[tex] t^{2} = 833.33 [/tex]

Taking the square root of both sides, we have;

[tex] t = \sqrt{833.33} [/tex]

Time, t = 28.87 seconds

A 4 mm object is observed by a magnifying lens as 1.25 cm. Calculate the ratio do/di.

Answers

Answer:

dₒ/dᵢ = 0.32

Explanation:

From the question given above, the following data were obtained:

Object height (Hₒ) = 4 mm

Image height (Hᵢ) = 1.25 cm

Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?

Next, we shall convert 4 mm to cm. This can be obtained as follow:

10 mm = 1 cm

Therefore,

4 mm = 4 mm × 1 cm / 10 mm

4 mm = 0.4 cm

Next, we shall determine the magnification of the lens. This can be obtained as follow:

Object height (Hₒ) = 4 mm

Image height (Hᵢ) = 1.25 cm

Magnification (M ) =?

M = Hᵢ/Hₒ

M = 1.25 / 0.4

M = 3.125

Finally, we shall determine the ratio of object distance (dₒ) to image distance (dᵢ). This can be obtained as follow:

Magnification (M) = 3.125

Ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] =?

Magnification (M) = image distance (dᵢ) / object distance (dₒ)

M = dᵢ/dₒ

Invert

1/M = dₒ/dᵢ

1/3.125 = dₒ/dᵢ

dₒ/dᵢ = 0.32

Therefore, the ratio of object distance (dₒ) to image distance (dᵢ) [dₒ/dᵢ] is 0.32

when is the acceleration of body is positive negative and zero?​

Answers

Answer:

【 In vector form , if angle between velocity vector and acceleration vector is less than 90° and greater than 0° then it is positive acceleration and if it is less than 180° and greater than 90° then it is negative acceleration. If there is no acceleration vector then it is called zero acceleration. 】

The density of oil is 0.8 g/cm^3. What is the mass of 36 cm^3 of oil? + (1 Point) O 0.29 N O 28.09 28.8 g O 36.89​

Answers

Answer:

density = mass/volume

density=0.8

volume=36

mass=?

0.8=mass/36

mass = 36x0.8=28.8g

if you use 75 N of force to lift and object and you do 300 Joules of work how far did you lift the object?​

Answers

Given W (work) = 300J

F (force) = 75N

s (displacement) = ?

We know that, W = Fs

So,

300 J = 75N × s

= 300J/75N = s

= 4m = s

So, I traveled 4m.

I need help answer these questions please

Answers

Answer:

1. 25 J

2. 250 J

3. 900,000 J

4. 7,500 J

Explanation:

1. The distance the wheelbarrow is tilted, d = 0.5 m

The force used to tilt the wheelbarrow, F = 50 N

The work done, W = F × d

∴ W = 50 N × 0.5 m = 25 J

2. Work done, W = Force × Distance

The applied force, F = 50 N

The distance the sand is moved, d = 5 m

∴ W = 50 N × 5 m = 250 J

3. The work done, W = The load lifted × The height to which the load is lifted

∴ W = 90,000 N × 10 m = 900,000 J

The work done, W = 900,000 J

4. The work output of the skateboard = The work input × Efficiency

Given that the skateboard is an ideal machine, we have;

The work output of the skateboard = The work input = W

W = F × d

F = 15 N, d = 500 m

∴ W = 15 N × 500 m = 7,500 J

The work output of the skateboard = W = 7,500 J.

Two tuning forks, 492 Hz and 498 Hz, are struck simultaneously. How many beats will be heard?

none
2.00 beats
4.00 beats
6.00 beats

Answers

Answer:

6 beats

If one fork beats once and another twice in the same time period

you would hear 1 beat. (Same for 2 and 3 beats).

Melanie gets into an accident on the highway that sends her to the hospital for three weeks with multiple broken bones. Her hospital bill totals over $32,000, but she discovers that the woman who hit her only has $25,000 worth of liability insurance.

Answers

20,000 because I did the quiz and got it right txt me if you need help

who is the father of computer but not Charles Babbage can anyone guess​

Answers

Answer:

It's Obusively charles Babbage I guess

what is the difference between static electricity produced by friction, conduction of electricity, and induction of an electrical charge?

Answers

Answer:

ummm a whole bunch

Explanation:

explain mass in physics​

Answers

Answer:

, a fundamental property of all matter. It is, in effect, the resistance that a body of matter offers to a change in its speed or position upon the application of a force. The greater the mass of a body, the smaller the change produced by an applied force.

Which type of radiation can reach the furthest?
A. Beta

B. Gamma

C. Alpha

Answers

Answer:

B. Gamma

Explanation:

The gamma radiation can travel much farther through air than alpha or beta.

"" damped force equation ""​

Answers

Answer:

In many vibrating systems the frictional force Ff can be modeled as being proportional to the velocity v of the object: Ff = −cv, where c is called the viscous damping coefficient.

A constant unbalanced force is applied to an object for a period of time. What will happen to the objects acceleration?

a. It will accelerate in the direction of the net force.
b. It will accelerate opposite the direction net force.
c. There is no acceleration.
d. Not enough information to answer

Answers

Answer:

A

Explanation:

The moving object will accelerate as long as a net force is applied. If a net force is not applied, the object will continue to move at a constant speed along the same path in curved spacetime (due to gravity). If the net force continues the velocity of the object will continue to increase until nearly reaching the limit (speed of light).

A HIGH SPEED TRAIN IS 180M LONG AND IT IS TRAVELLING AT 50M/S.HOW LONG WILL IT TAKE TO PASS A PERSON STANDING AT A LEVEL CROSSING?



B-HOW LONG WILL IT TAKE TO PASS COMPLETELY THROUGH A STATION WHOSE PLATFORMS ARE 220M IN LENGTH?

Answers

Answer:

a. Time = 3.6 seconds

b. Time = 4.4 seconds

Explanation:

Given the following data;

Distance = 180 m

Speed = 50 m/s

a. To find the time;

Speed can be defined as distance covered per unit time. Speed is a scalar quantity and as such it has magnitude but no direction.

Mathematically, speed is given by the formula;

[tex]Speed = \frac{distance}{time}[/tex]

Making time the subject of formula, we have;

[tex]Time = \frac{distance}{speed}[/tex]

Substituting into the equation, we have;

[tex]Time = \frac{180}{50}[/tex]

Time = 3.6 seconds

b. Distance = 220 meters

Speed = 50 m/s

To find the time;

[tex]Time = \frac{distance}{speed}[/tex]

Substituting into the equation, we have;

[tex]Time = \frac{220}{50}[/tex]

Time = 4.4 seconds

Which statement about momentum is false? a. Momentum is a force b. Momentum may be transferred c. Momentum is always conserved d. Momentum is a property only of moving objects

Answers

Answer:

So, option(a).

Explanation:

Momentum is the measure of motion of the object.

Momentum is given by the product of mass and the velocity of the object.

(a) It is false.

(b) It is true, momentum is transferred.

(c) It is true, As the momentum of the system is conserved when no external force is applied on the system.

(d) It is true, as the momentum is associated with the velocity of the object.

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