While walking on ice one should take small steps to avoid slipping. This is because smaller steps ensure
(1) Larger friction
(2) Smaller friction
(3) Larger normal force
(4) Smaller normal force
A block is placed on a rough horizontal plane. A time dependent horizontal force, \(F=kt,\) acts on the block. The acceleration time graph of the block is :
1. | 2. | ||
3. | 4. |
A motorcycle is going on an overbridge of radius \(R\). The driver maintains a constant speed.
The normal force on the motorcycle as it ascends the overbridge will be:
1. increases.
2. decreases.
3. remains the same.
4. fluctuates erratically.
Two blocks A and B of masses m & 2m respectively are held at rest such that the spring is in natural length. Find the accelerations of both the blocks just after release.
(1)
(2)
(3) (0, 0)
(4)
Two masses, \(M\) and \(m\), are attached to a vertical axis by weightless threads of combined length \(l\). They are set in rotational motion in a horizontal plane about this axis with constant angular velocity \(\omega\). If the tensions in the threads are the same during motion, the distance of \(M\) from the axis is:
1. \(\frac{M l}{M + m}\)
2. \(\frac{m l}{M + m}\)
3. \(\frac{M+m}{M}l\)
4. \(\frac{M+m}{m}l\)
A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved
(1) 14 m/s
(2) 3 m/s
(3) 3.92 m/s
(4) 5 m/s
A point mass m is suspended from a light thread of length l, fixed at O, is whirled in a horizontal circle at constant speed as shown. From your point of view, stationary with respect to the mass, the forces on the mass are
(1) | |
(2) | |
(3) | |
(4) |
A motor cycle driver doubles its velocity when he is having a turn. The force exerted outwardly will be
(1) Double
(2) Half
(3) 4 times
(4) times
A mass is supported on a frictionless horizontal surface. It is attached to a string and rotates about a fixed centre at an angular velocity ω0. If the length of the string and angular velocity are doubled, the tension in the string which was initially T0 is now
(1) T0
(2) T0/2
(3) 4 T0
(4) 8 T0
An object with a mass 10 kg moves at a constant velocity of 10 m/sec. A constant force then acts for 4 second on the object and gives it a speed of 2 m/sec in opposite direction. The acceleration produced in it, is
(1) 3 m/sec2
(2) –3 m/sec2
(3) 0.3 m/sec2
(4) –0.3 m/sec2