1. Two blocks of masses m and m are connected as shown in the figure.
The acceleration of the block
m is:
1 2
2
m2 g m1 g 4 m2 g m1 g m2 g
(A*) (B) (C) (D)
m1 m2 m1 m2 m1 m2 m1 4 m2
2 block A of mass M so that the tension in light string also becomes F when block B of mass m acquires an
equilibrium state with respect to block A. Find the force F. Give your answer in terms of m, M and g.
mg
F=
m
2
1
m M
3. A boy and a block, both of same mass, are suspended at the same horizontal level, from each end of a light
string that moves over a frictionless pulley. The boy starts moving upwards with an acceleration 2.5 m/s2
relative to the rope. If the block is to travel a total distance 10 m before reaching at the pulley, the time taken
by the block in doing so is equal to :
10
m
m
10
(A) 8s (B*) 4s (C) s (D) 8s
2
4.
In the position shown collar B moves to the left with a velocity of 150 mm/s. Determine:
(a) the velocity of collar A
(b) the velocity of portion C of the cable
=
(c) the relative velocity of portion C of the cable
with respect to collar B.
[ Ans.: VA = 300 right, VC = 600 left, VCB = 450 left ]
5. A wedge of height h is released from rest with a light particle P placed on it as shown . The wedge slides down
aninclinewhichmakesananglewiththehorizontal. Allthesurfacesaresmooth,Pwillreachthesurfaceoftheinclinein
time :
2h 2h 2h 2h
(A*) (B) (C) (D)
gsin
2
gsincos gtan gcos 2
6. A system is shown in the figure. A man standing on the block is pulling the rope. Velocity of the point of string
in contact with the hand of the man is 2 m/s downwards. The velocity of the block will be: [ assume that the
block does not rotate ]
(A) 3 m/s (B*) 2 m/s (C) 1/2 m/s (D) 1 m/s
Sol. (B)
7. A hinged construction consists of three rhombus with the ratio of sides (5 : 3 : 2). Vertex A3 moves in the
horizontal direction with velocity V. Velocity of A will be :
(A) 2.5 V (B) 1.5V (C) (2/3)V (D*) 0.8V
8. In the pulley system shown in figure, block C is going up at 2 m/s and block B is going up at 4 m/s, then
the velocity of block A on the string shown in figure, is equal to
(A) 2 m/s (B*) 4 m/s (C) 6 m/s (D) 8 m/s
9. Figure shows two blocks A and B connected to an ideal pulley string system. In this system when bodies are
released then : (neglect friction and take g = 10 m/s2)
(A) Acceleration of block A is 1 m/s2
(B*) Acceleration of block A is 2 m/s2
(C) Tension in string connected to block B is 40 N
(D*) Tension in string connected to block B is 80 N
10. A cart of mass 0.5 kg is placed on a smooth surface and is connected by a string to a block of mass 0.2 kg.
At the initial moment the cart moves to the left along a horizontal plane at a speed of 7 m/s. (Use g = 9.8 m/s2)
0.5 kg
0.2 kg
(A*) The acceleration of the cart is 2
(B*) The cart comes to momentary r7est after 2.5 s.
(C*) The distance travelled by the cart in the first 5s is 17.5 m
.(D) The velocity of the cart after 5s will be same as initial velocity
2
11. A painter is applying force himself to raise him and the box with an acceleration of 5 m/s by a massless
rope and pulley arrangement as shown in figure. Mass of painter is 100 kg and that of box is 50 kg. If g =
10 m/s2, then:
tension in the rope is 1125 N
(A*)
(B) tension inthe rope is 2250 N (jLlhesa ruko 2250 N)
(C*) f orce of contac t betwe en the painter and the floor is 375 N
(D) none of these
12. A rod AB is shown in figure. End A of the rod is fixed on the ground. Block is moving with velocity
3 m/s towards right. The velocity of end B of rod when rod makes an angle of 60º with the ground is:
(A) 3 m/s (B*) 2 m/s (C) 2 3 m/s (D) 3 m/s
13. In the Figure, the blocks are of equal mass. The pulley is fixed & massless. In the position shown, A is
given a speed u and vB= the speed of B. (< 90°)
///
/ ///
/ ///
//
B
u
A
(A*) B will never lose contact with the ground
(B) The downward acceleration of A is equal in magnitude to the horizontal acceleration of B.
(C) vB = u cos
(D*) vB = u/cos
14. In the Figure, the pulley P m ove s to the right with a constant speed u. The downward speed of A is vA,
and t he s peed of B t o the right is v
(A) vB = vA (B*) vB = u + vA
(C) vB + u = vA
(D*) the two blocks have accelerations of the same magnitude
