Fig. shows the position-time graph of a particle of mass 4 kg. What is

1.	Fig. shows the position-time graph of a particle of mass 4 kg. What is the (a) Force on the particle for t < 0, t > 4s, 0 < t < 4s ? (b) Impulse at t = 0 and t = 4s ? (Consider one dimensional motion only)
Answer» (a) For t < 0. No force as Particles is at rest. For t > 4s, No force again particle comes at rest. For 0 < t < 4s, as slope of OA is constant so velocity constant i.e., a = 0, so force must be zero. (b) Impulse at t = 0 Impulse = change in momentum I = m(v – u) = 4(0 – 0·75) = 3 kg ms^–1 Impulse at t = 4s I = m (v – u) = 4 (0 – 0.75) = – 3 kg ms^–1

Fig. shows the position-time graph of a particle of mass 4 kg. What is the (a) Force on the particle for t < 0, t > 4s, 0 < t < 4s ? (b) Impulse at t = 0 and t = 4s ? (Consider one dimensional motion only)

Answer»

(a) For t < 0. No force as Particles is at rest.

For t > 4s, No force again particle comes at rest.

For 0 < t < 4s, as slope of OA is constant so velocity constant i.e., a = 0, so force must be zero.

(b) Impulse at t = 0

Impulse = change in momentum

I = m(v – u) = 4(0 – 0·75) = 3 kg ms^–1

Impulse at t = 4s

I = m (v – u) = 4 (0 – 0.75) = – 3 kg ms^–1