Work Power Energy

A body initially at rest and sliding along a frictionless track from a height $h$ (as shown in the figure) just completes a vertical circle of diameter $AB=D$. The height $h$ is equal to,

Which of the following statements is false for a particle moving in a circle with a constant angular speed?

A block of mass 10 kg, moving in x direction with a constant speed of 10 m s-1 , is subjected to a retarding force F=(0.1)x J m-1 during its travel from x=20 m to 30 m . Its final kinetic energy will be:

A force F=20+10y acts on a particle in y-direction where F is in Newton and y is in meter. Work done by this force to move the particle from y=0 to y=1 m is

An electric lift with a maximum load of \$2000kg$ (lift \$+$ passengers) is moving up with a constant speed of \$1.5ms^{-1}$. The frictional force opposing the motion is \$3000N$. The minimum power delivered by the…

Two similar springs P and Q have spring constants KP and KQ, such that KP>KQ. They are stretched, first by the same amount (case a), then by the same force (case b). the work done by the springs WP and WQ are related as…

A particle moves from a point - 2i^+5j^ to 4j^+3k^ when a force of 4i^+3j^ N is applied. How much work has been done by the force?

The energy that will be ideally radiated by a \$100kW$ transmitter in \$1$ hour is

A body of mass 1 kg begins to move from rest under the action of a time dependent force F$\rightarrow$=2t i^+3t2 j^N, where i^and j^ are unit vectors along x and y axis. What power will be developed by the force at the…

The potential energy of a long spring when stretched by \$2cm$ is \$U$. If the spring is stretched by \$8cm$, potential energy stored in it will be:

A particle of mass $M$ moves along a horizontal $x$ axis from $x=0$ to $x=L$. The coefficient of kinetic friction varies as a function of $x$ as $\mu_k(x)=\mu_0-\alpha x$, where $\mu_0$, $\alpha$ are constants of…

The power of a crane, which lifts a mass of $1000$ kg to a height of $20$ m in $10$ s is : ($g = 9.8$ m/s$^2$)