Question

A body of mass 3 kg is under a constant force
which causes a displacement s in metres in it,
given by the relation s =
t²/3, where t is in s
Workdone by the force in 2 s is​

Answer 1

Answer:

8/3 J

Explanation:

Answer 2

Answer:

Work done 8/3 or 2.67 J.

Explanation:

Given,

A body of mass 3 kg is under a constant force which causes a displacement s in metres in it, given by the relation s = t²/3, where t is in sec.

To find: Work done by the force in 2 s

Solution:

Equation of displacement = t²/3 = 1/3 t²

Displacement at t = 2, ==> (2)² / 3 = 4/3

Differentiate wrt. 't' we will obtain velocity.

v = (2/3) *t

Differentiate wrt. 't' again, we will obtain acceleration.

a = 2/3 m/s²

Then, Force = mass * acceleration

or, F = ma = 3 * 2/3 = 2 N

Work done = force * displacement

or, W = f.d = 2 * 4/3 = 8/3 = 2.67 J

Therefore, Work done 8/3 or 2.67 J.