Work Energy and...

How much height must an object of mass $$5kg$$ be lifted to have potential energy $$5000J$$ ?$$[g=10 m/s^2]$$

The block will again collide after time:

How many collision are possible between the blocks?

A car is accelerated on a levelled road and attains a speed of $$5$$ times its initial speed. In this process , the kinetic energy of the car:

When a stone of mass 'm' falls through a vertical height 'd', the decrease in the gravitational energy is:

Potential energy of a person is minimum when:

A car is accelerated on a leveled road and attains a velocity $$4$$ times its initial velocity. In this process, the potential energy of the car:

An object of mass $$5 \,kg$$ falls from a height of $$5 \,m$$ above the ground. The loss of potential energy of the mass is:

When a boy triples his speed, his kinetic energy becomes 

A position dependent force $$ F = 7 - 2x + 3x^2 $$ newton acts on a small body of mass $$2 $$ kg displace it from $$ x = 0$$ to $$ x = 5 m $$ the work done in joules is