What is the mass of an object travelling at 15 m/s with a kinetic energy of 100 J?

Kinetic Energy (Ek) = 1/2(mv2).This can be rearranged such that, m = (2Ek)/v2we know from the question that E= 100 J and we know that v = 15 m/sso plugging in the numbers, we get m = (2 x 100)/(15)2 = 200/225 = 0.89 Kg (to 3 significant figures)

TD

Related Physics GCSE answers

All answers ▸

A mass of 2kg is dropped from rest at a height of 10m. i) What is the initial GPE of the mass? ii) What is the final velocity of the mass when it hits the ground?


Car 1 has a of mass 1000kg and is going at 20m/s. Car 2 has the same mass as Car 1 and is stationary. If they collide and travel together as one unit in the same direction as Car 1 was going, calculate the speed of the unit after the collision.


Why do we use non-renewable energy?


a )John heats up 2kg of water from 20 degrees c to 80 degrees c. How much energy input did this require? b )When John weighs the water at the end, he has less than he started with. Why might this be? c) What hazards are in this experiment?