A bicyclist comes to a skidding stop in \(10\) m. During this process, the force on the bicycle due to the road is \(200\) N is directly opposed to the motion. The work done by the cycle on the road is:
1. | \(+2000\) J | 2. | \(-200\) J |
3. | zero | 4. | \(-20000\) J |
The potential energy of a system increases if work is done:
1. by the system against a conservative force.
2. by the system against a non-conservative force.
3. upon the system by a conservative force.
4. upon the system by a non-conservative force.
A bolt of mass 0.3 kg falls from the ceiling of an elevator moving down at a uniform speed of 7 m/s. It hits the floor of the elevator (length of the elevator = 3 m) and does not rebound. What is the heat produced by the impact?
1. 8.82 J
2. 7.65 J
3. 7.01 J
4. 7.98 J
A body of mass 0.5 kg travels in a straight line with velocity where . What is the work done by the net force during its displacement from x = 0 to x = 2 m?
1. 50 J
2. 45 J
3. 68 J
4. 90 J
The bob of a pendulum is released from a horizontal position. If the length of the pendulum is 1.5 m, what is the speed with which the bob arrives at the lowermost point, given that it dissipated 5% of its initial energy against air resistance?
1. 2.5 m/s
2. 3.9 m/s
3. 4.7 m/s
4. 5.3 m/s
A mass is performing a vertical circular motion (see figure.) If the average velocity of the particle is increased, then at which point the string will break?
1. | A | 2. | B |
3. | C | 4. | D |
The bob of a simple pendulum having length l, is displaced from the mean position to an angular position θ with respect to vertical. If it is released, then the velocity of the bob at the lowest position will be:
1.
2.
3.
4.
A ball is dropped from a height of \(5\) m. If it rebounds up to a height of \(1.8\) m, then the ratio of velocities of the ball after and before the rebound will be:
1.
2.
3.
4.
A particle of mass m1 is moving with a velocity v1 and another particle of mass m2 is moving with a velocity v2. Both of them have the same momentum, but their kinetic energies are E1 and E2 respectively. If m1 > m2 then:
1.
2.
3.
4.
A mass of \(0.5\) kg moving with a speed of \(1.5\) m/s on a horizontal smooth surface, collides with a nearly weightless spring with force constant \(k=50\) N/m. The maximum compression of the spring would be:
1. \(0.12\) m
2. \(1.5\) m
3. \(0.5\) m
4. \(0.15\) m