Recent content by RachelT

Haha yeah 2dp, that's the English way (guessing your not English?)

Tried again and got total energy loss of 137995.2 J. Is this right?

Thankyou

Homework Statement Using formulae for PE and KE, find the speed that a tennis ball hits the ground when dropped from 20m. Homework Equations m x g x h and 1/2 x m x v^2 The Attempt at a Solution PE=KE Mgh = 1/2mv^2 (masses cancel out) 9.8 x 20.= 1/2 v^2 196 = 1/2 v^2 196/...

sorry. I forgot to turn that PE into KE by making 196 = 1/2v^2 This would give 19.79m/s

Homework Statement Using the formulae for potential energy and kinetic energy, find the speed that a tennis ball hits the ground when dropped from a height of 20m. With reference to the principle of conservation of energy, explain why you could use these equations and what assumptions you...

yes thank you sophiecentaur. I have now converted and have a velocity of 10.26m/s. using this answer for the next part I had an energy loss of 105,637.96J. Can you tell me if these answers are correct. If not I will keep plugging away. Thanks for your time :-)

first post so here goes: this question isn't hard but i can't seem to get the answer i should have. 'a car of mass 1050kg runs into the back of car b which is stationary with mass 1200kg. car A was moving at 50mph immediately before impact. after impact, the vehicles are locked together'...

first post so here goes: this question isn't hard but i can't seem to get the answer i should have. 'a car of mass 1050kg runs into the back of car b which is stationary with mass 1200kg. car A was moving at 50mph immediately before impact. after impact, the vehicles are locked together'...