The energy, e possessed by an object of a mass m kg traveling at a speed of vm/s 1/2 mv^2joules (a) express v interms of e and m (b) if the energy of a 50 kg mass is 4900 joules, how it is moving?

(a)

(b) It is moving at 14 m/s.

Explanation:

(a)

Given:

The energy, , of an object moving with a velocity is given as:

, where, is its mass.

Multiplying both sides by 2, we get

Now, divide both sides by

Taking square root both sides, we get

Therefore, in terms of and is given as:

(b)

Using the above formula,

Plug in 4900 joules for and 50 kg for . Solve for . This gives,

Therefore, it is moving with a speed of 14 m/s.

we need to know the time interval during which the force acts. impulse of force = momentum change