Work, Energy and Power MCQ (NEET, JEE Main) – Test 4 1

A body of mass 1 kg begins to move under the action of a time dependent force , where  are unit vectors along x and y axis. What power will be developed by the force at the time t? [NEET UG 2016]

A nucleus at rest splits into two nuclear parts having radii in the ratio 1: 2. Their velocities are in the ratio [Karnataka CET 2015]

A bob of mass M is suspended by a massless string of length L. The horizontal velocity V at position A is just sufficient to make it reach the point B. The angle θ at which the speed of the bob is half of that at A, satisfies [IIT JEE 2008]

Figure:

A block (B) is attached to two unstretched springs S1 and S2 with spring constants k and 4k, respectively (see figure I). The other ends are attached to identical supports M1 and M2 not attached to the walls. The springs and supports have negligible mass. There is no friction anywhere. The block B is displaced towards wall 1 by a small distance x (figure II) and released. The block returns and moves a maximum distance y towards wall 2. Displacements x and y are measured with respect to the equilibrium position of the block B. The ratio y/x is [IIT JEE 2008]

A block of mass 0.50 kg is moving with a speed of 2.00 ms^–1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is [AIEEE 2008]