Question

Certain force acting on a 20 kg mass changes its velocity from
5 m s- to 2 m s-l. Calculate the work done by the force.​

Answer 1

Explanation:

DATA:

mass = 20 kg

initial velocity = vi = 5 ms

final velocity = vf = 2 ms

Work done = W = ?

SOLUTION:

acceleration = a ; Weight = W

⭕ W = mg

W = 20 × 9.8

W = 196 N

W = F

⭕F = ma

a = F / m

a= 196 / 20

a = 9.8 ms^-2

⭕2aS = vf2 - vi2

S = vf2 - vi2 / 2a

S = (2)2 - (5)2 / 2(9.8)

S = 4 - 25 / 19.6

S = 2.72 m

⭕ W = F × S

W = 196 × 2.72

W = 533.1 N