A uniform force of (3i + j) N acts on a particle of mass 2 kg. Hence the particle is displaced from position (2i+k) m to position (4i+3j-k) m. The work done by the force on the particle is-
1. 9J
2. 6J
3. 13J
4. 15J
An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms-1 and the second part of mass 2kg moves with 8 ms-1 speed. If the third part flies off with 4 ms-1 speed, then its mass is
1. 3kg
2. 5kg
3. 7kg
4. 17kg
Two spheres A and B of masses respectively collide. A is at rest initially and B is moving with velocity v along x-axis. After collision B has a velocity in a direction perpendicular to the original direction.The mass A moves after collision in the direction
1. same as that of B
2. opposite to that of B
3.
4.
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 nonconservative force
(3) upon the system by a conservative force
(4) upon the system by a nonconservative force
Force F on a particle moving in a straight line varies with distance d as shown in the figure. The work done on the particle during its displacement of 12 m is
(a) 21 J (b) 26 J
(c) 13 J (d) 18 J
A ball moving with velocity collides head on with another stationery ball of double the mass. If the coefficient of restitution is 0.5, then their velocities (in ) after collision will be
(1)0,1
(2)1,1
(3)1,0.5
(4)0,2
A particle of mass M starting from rest undergoes uniform acceleration. If the speed acquired in time T is v, the power delivered to the particle is
1.
2.
3.
4.