Question

a 1 kg block b rests as shown on a bracket a of same mass.constant forces f1=20n and f2=8n start to act at a time t=0 when distance of block b from pulley is 50cm.time when block b reaches the pulley is

Answer 1

Given :-

Mass of block = 1 Kg

Distance to be travelled = S = 50 cm = 0.5 m

Considering the force F1's direction as positive.

Force F1 acting on body = 20 N

Force F2 acting on body = 8 N

Net force Acting on the body,

F = F1 + F2

F = 20 + (-8)

F = 12 N

Finding the acceleration of the body,

F = ma

12 = a

a = 12 ms-²

Using second equation of Motion to find time when body will cover 0.5 m distance.

Body is initially at rest.

u = 0 ms-¹

S = 1/2 at²

0.5 = 1/2 × 6 × t²

t² = 0.5/3

t² = 0.16

t² = (0.04)²

t = 0.04 s

Hence,

Time taken to cover 0.5 m distance = t = 0.04 s.