Question

Find the acceleration pf the blocks a and b in the three situation

Answer 1

6. A particle of mass 50 g moves on a straight line. The variation of speed with time is shown in figure (5-E1). Find the force acting on the particle at t = 2, 4 and 6 seconds.

Sol:

We know that,

Slope of the curve in velocity v/s time graph = acceleration

Therefore, a@ 2 s = (15/3) = 5 m/s2; a@ 4 s = 0 m/s2; a@ 6 s = – (15/3) = – 5 m/s2.

We have, Force = mass * acceleration

So, F@ 2s = (50/1000) * 5

Or, F@ 2s = 0.25 N along the motion.

→ F@ 4s = (50/1000) * 0 = 0.

→ F@ 6s = (50/1000) * (– 5)

Or, F@ 6s = – 0.25 or 0.25 N opposite to the motion.

7. Two blocks A and B of mass mA and mB respectively are kept in contact on a frictionless table. The experimenter pushes the block A from behind so that the blocks accelerate. If the block A exerts a force F on the block B, what is the force exerted by the experimenter on A?

Sol:

Given: mass of two blocks A and B are mA and mB respectively. Force exerted by block A on Block B is F. Therefore, the force exerted on block A by block B is also F. Let, the force exerted by the experimenter on A be P and acceleration be a.

thanks