Ask question

Ask question

All categories

3 years ago

14

How to use kinetic energy to calculate velocity

1 answer:

BartSMP [9]3 years ago

7 0

As we know the formula of kinetic energy is

$KE = \frac{1}{2} mv^2$

here given that

KE = 150,000 J

mass = 120 kg

we can use this to find speed

$150,000 = \frac{1}{2} * 120 * v^2$

$v^2 = 2500$

$v = 50 m/s$

So speed of above object is 50 m/s

You might be interested in

What provides the centripetal force needed to keep Earth in orbit?

kkurt [141]

The centripetal force needed to keep earth in orbit is gravity.

3 0

3 years ago

Read 2 more answers

| A T-ball with a mass of 0.6 kg travels in the

r-ruslan [8.4K]

Answer:

$|I|=6\ Kg.m/s$

$F=120\ N$

Explanation:

Impulse and Momentum

They are similar concepts since they deal with the dynamics of objects having their status of motion changed by the sudden application of a force. The momentum at a given initial time is computed as

$p_o=m.v_o$

When a force is applied, the speed changes to $v_1$ and the new momentum is

$p_1=m.v_1$

The change of momentum is

$\Delta p=p_1-p_0=m(v_1-v_o)$

The impulse is equal to the change of momentum of an object and it's defined as the average net force applied times the time it takes to change the object's motion

$I=F.t=\Delta p$

Part 1

The T-ball initially travels at 10 m/s and then suddenly it's stopped by the glove. The final speed is zero, so

$\Delta p=0.6\ Kg(0-10\ m/s)=-6\ Kg.m/s$

The impulse is

$I=\Delta p$

$I=-6\ Kg.m/s$

The magnitude is

$|I|=6\ Kg.m/s$

Part 2

The force can be computed from the formula

$I=F.t$

The direction of the impulse the T-ball receives is opposite to the direction of the force exerted by the ball on the glove, thus $I_b=6\ kg.m/s$

$\displaystyle F=\frac{I}{t}=\frac{6\ kg.m/s}{0.05\ s}$

$\boxed{F=120\ N}$

7 0

3 years ago

A rock is thrown horizontally off a cliff with an initial speed of 3 m/s. The initial position of the rock is 10 meters above th

Valentin [98]

Answer:

<em>1.43 s.</em>

Explanation:

Using one of the equations of motion,

S = ut + 1/2gt².......................... Equation 1

Where S = height of the cliff, u = initial velocity, t = time, g = acceleration due to gravity.

<em>Note: When the rock begins to fall from the maximum height, u = 0 m/s, g = positive</em>

<em>Given: S = 10 m, u = 0 m/s</em>

<em>Constant: g = 9.8 m/s²</em>

<em>Substituting these values into equation,</em>

<em>10 = 0(t) + 1/2(9.8)(t²)</em>

<em>10 = 0 + 4.9t²</em>

<em>t² = 10/4.9</em>

<em>t² = 100/49</em>

<em>t = √(100/49)</em>

<em>t = 10/7</em>

<em>t = 1.43 s.</em>

<em>Thus the rock spend 1.43 s in air</em>

3 0

3 years ago

a camcorder has a power rating of 19 watts. If the output voltage from its battery is 5 volts, what current does it use

Mama L [17]

3.8 amperes
work: 19w/5v=3.8amps

8 0

3 years ago

Material A has a higher thermal conductivity than Material B. Which material will transfer energy by conduction faster?

AlladinOne [14]

Answer: a

Explanation:

7 0

3 years ago