Question

Force of 4 N is applied on a body of mass 20 kg.
The work done in 3rd sec. is
(1) 3 Joule
(2) 2 Joule
(3) 4 Joule
(4) 1 Joule​

Answer 1

Explanation:

Force = 4N and mass of body = 20 kg

Time at which work needs to be found = 3rd second

Force(f) = Mass(m) x Acceleration(a)

Therefore, Acceleration(a) = Force/Mass = 4/20 = 1/5 ms⁻² = 0.2 ms⁻²

Taking Intial velocity (u) = 0 ms⁻¹

Displacement =  ut+1/2at² = 0.5 x 0.2 x 3² = 0.1 x 9 = 0.9 m

Work = Force x Displacement = 4 x 0.9 =3.6 J

Answer 2

Answer:

✅Here's your answer

Given

. F= 4N

m= 20kg

T = 3 sec

☯F = ma

4/20 = a

✔0.2 m /sec^2 = a

☯Since work done = force ×displacement....

☯s=ut+1/2 at^2

s= 0+0.1×9

✔s= 0.9 m

☯WORK DONE = 4×0.9

✔= 3.6 Joule

Hope it helps ✌