Question

A body of mass 6 kg is acted upon
by a force which causes a
12
displacement in it given by x
m
4
where t is the time in second. The
work done by the force in 2 second
is​

Answer 1

Explanation:

M =6 kg, dis. = x T,=2 sec F=12N

F=ma

12=6a

a=2

s=ut+1/2at`2

x=0×2+1/2×2×2

x=4 W=fs

12×4 =48

Answer 2

Answer:

W=3j

Explanation:

The displacement of a body is given by x=

4

t

2

∴ Velocity, v=

dt

dx

=

4

1

×2t=

2

t

Initial velocity, u=v

∣

∣

∣

∣

∣

t=0

=0

Final velocity, v=v

∣

∣

∣

∣

∣

t=2

=

2

2

=1 m/s

From work-energy theorem, W=ΔK.E

W=

2

1

mv

2

−

2

1

mu

2

W=

2

1

×6×1

2

−0

⇒ W=3J