Advertisements
Advertisements
Question
In the previous problem, suppose m2 = 2.0 kg and m3 = 3.0 kg. What should be the mass m, so that it remains at rest?
Advertisements
Solution

For m1 to be at rest, a1 = 0.
T − m1g = 0
T = m1g ...(i)
For mass m2,
T/2 − 2g = 2a
T = 4a + 4g ...(ii)
For mass m3,
3g – T/2= 2a
T = 6g − 6a ...(ii)
From equations (ii) and (iii), we get:
3T – 12g = 12g – 2T
T = 24g/5= 4.08g
Putting the value of T in equation (i), we get:
m1 = 4.8kg
APPEARS IN
RELATED QUESTIONS
A block of mass m is placed on a smooth wedge of inclination θ. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block has a magnitude.
The figure shows the displacement of a particle going along the X-axis as a function of time. The force acting on the particle is zero in the region

(a) AB
(b) BC
(c) CD
(d) DE
Two blocks of equal mass m are tied to each other through a light string. One of the blocks is pulled along the line joining them with a constant force F. Find the tension in the string joining the blocks.
A particle of mass 50 g moves in a straight line. The variation of speed with time is shown in the following figure. Find the force acting on the particle at t = 2, 4 and 6 seconds.

A man has fallen into a ditch of width d and two of his friends are slowly pulling him out using a light rope and two fixed pulleys as shown in the following figure. Show that the force (assumed equal for both the friends) exerted by each friend on the road increases as the man moves up. Find the force when the man is at a depth h.
Suppose the ceiling in the previous problem is that of an elevator which is going up with an acceleration of 2.0 m/s2. Find the elongation.
An empty plastic box of mass m is found to accelerate up at the rate of g/6 when placed deep inside water. How much sand should be put inside the box so that it may accelerate down at the rate of g/6?
Consider the situation shown in the following figure All the surfaces are frictionless and the string and the pulley are light. Find the magnitude of acceleration of the two blocks.

Consider the situation shown in the following figure. Both the pulleys and the string are light and all the surfaces are frictionless.
- Find the acceleration of the mass M.
- Find the tension in the string.
- Calculate the force exerted by the clamp on the pulley A in the figure.

A body of mass m moving with a velocity v is acted upon by a force. Write an expression for change in momentum in each of the following cases: (i) When v << c, (ii) When v → c and (iii) When v << c but m does not remain constant. Here, c is the speed of light.
A force of 10 N acts on a body of mass 2 kg for 3 s, initially at rest. Calculate : Change in momentum of the body.
An electron of mass 9 × 10−31 kg is moving with a linear velocity of 6 × 107 ms−1. Calculate the linear momentum of electron.
Multiple Choice Question. Select the correct option.
A force acts on a body of mass 3 kg such that its velocity changes from 4 ms−1 to 10 ms−1. The change in momentum of the body is
Name the physical entity used for quantifying the motion of a body.
State Newton's second law of motion. Is Newton's first law of motion contained in Newton's second law of motion?
A stone is thrown vertically upward with a velocity of 9.8 m/s. When will it reach the ground?
A body of mass 2 kg travels according to the law x(t) = pt + qt2 + rt3 where p = 3 ms−1, q = 4 ms−2 and r = 5 ms−3. The force acting on the body at t = 2 seconds is ______.
According to Newton's Second Law of Motion, what quantity is directly proportional to the applied force?
