Question

. Certain force acting on a 20 kg mass change it's velocity from 5m/s to 2m/s calculate the work alone by the force?

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Answer 1

Explanation:

Here , given mass = 20 kg initial velocity (u) = 5 m/sec final velocity ... Calculate the work done by the force. 2 ... (2ms -1)² - (5ms-1)² = 2 x (-3ms-²) x s ... so, work = m × a× s

Answer 2

Given that, a body of mass 20 kg got its velocity changed from 5m/s to 2m/s by a certain force.

We need to find the work done by the force.

Here, The kinetic energy of the body changes hence the change in the kinetic energy would be work done by the force.

Because, Of the law of conservation of energy, The force applied will cancel out an amount of energy from the body. The amount of energy depend on the quantity of force.

⇒ △K.E = (mu²)/2 - (mv²)/2

⇒ △K.E = (20×5²)/2 - (20×2²)/2

⇒ △K.E = 10×25 - 10×4

⇒ △K.E = 250 - 40

⇒ △K.E = 210 Joules

Hence, 210 Joules of work is done by the force.

Some Information :-

☛ Kinetic energy is the energy possessed by a body due to its motion.

Kinetic Energy = 1/2 × Mass × Velocity ²