Work Power & Energy

The velocity-time graph for a body of mass 10 kg is shown in the figure. Work done on the body in the first two seconds of motion is :

The following figure shows the variation of potential energy \(V(x)\) of a particle with distance \(x\). The particle has

A train is moving along the tracks at a constant speed u. A girl on the train throws a ball of mass m straight ahead along the direction of motion of the train with speed \(\mathrm{v}\) with respect to herself. Then

A uniform rope of length 4 m and mass 0.4 kg is held on a frictionless table in such a way that 0.6 m of the rope is hanging over the edge. The work done to pull the hanging part of the rope on to the table is, (Assume g = 10 m/s\(^2\))

A particle is moving in x-y plane according to \(\overrightarrow r = b\cos \omega t\widehat i + b\sin \omega t\widehat j\), where \(\omega\) is constant. Which of the following statement(s) is/are true?

The kinetic energy (Ek) of a particle moving along X-axis varies with its position (X) as shown in the figure. The force acting on the particle at X = 10 m is

The potential energy of a particle of mass 0.02 kg moving along X-axis is given by V = Ax (x \(-\) 4) J, where x is in metre and A is a constant. Which of the following statements is/are correct?

A block of mass m slides with speed v on a frictionless table towards another stationary block of mass m. A massless spring with spring constant k is attached to the second block as shown in figure. The maximum distance, the spring gets com...

Consider an engine that absorbs 130 cal of heat from a hot reservoir and delivers 30 cal heat to a cold reservoir in each cycle. The engine also consumes 2 J energy in each cycle to overcome friction. If the engine works at 90 cycles per mi...

A body starts from rest, under the action of an engine working at a constant power and moves along a straight line. The displacement s is given as a function of time (t) as

A bullet of mass 4.2 \(\times\) 10\(-\)2 kg, moving at a speed of 300 ms\(-\)1, gets stuck into a block with a mass 9 times that of the bullet. If the block is free to move without any kind of friction, the heat generated in the process w...

Work done for a certain spring when stretched through 1 mm is 10 joule. The amount of work that must be done on the spring to stretch it further by 1 mm is

A body of mass 3 kg acted upon by a constant force is displaced by S meter, given by relation \(S = {1 \over 3}{t^2}\), where t is in second. Work done by the force in 2 seconds