A particle of mass 5kg is acted upon by a force of 400N for a distance of 20m along the x axis. What is its final velocity if it is initally at rest?

The work done by a force on a particle is: Work done = Force x Displacement.The energy of a particle is given by the sum of its potential and kinetic energies.As the particle does not gain or lose any height (in the y axis), only its kinetic energy changes.Therrfore the work done by the force is 400(N) x 20(m) = 8000(J).This is equal to its change in kinetic energy = 0.5 x m x v2 . = 0.5 x 5 x v2.By algebra: sqrt(2x8000/5) = v = 56.6ms-1.

LT

Related Physics GCSE answers

All answers ▸

If a 60kg girl jumps out of a helicoptor, draw diagrams to show the forces (with values) acting on her when a) she is in freefall, b) she is accelerating at half of g (g = 10 m/s^2), c) she is travelling at a constant speed?


Draw diagrams to represent the particles in each state: solid, liquid, and gas.


Why do windows around the house steam up?


Explain why a simple electric motor continues to turn in the same direction when there is a current in the coil (6 marks)