Which of the following has the most kinetic energy a 25-kg fish tank sitting on a table, a 50-kg fish swimming in a fish tank, a 7,500-kg car parked on a steep hill, or a 50-kg boulder suspended from a cliff .

Aball of mass 0.3kg is released from rest at a height of 8m. how fast is it going when it hits the ground? accleration due to gravity is g=9.8m/s

20) what is a magnetic field? 21) in which direction do magnetic field lines always point? 22) sketch a diagram showing how a plotting compass points around a 23) name two magnetic poles that will: a) attract each other b) repel each other. 24) explain why you can use a compass to navigate. 25) what's an electromagnet? 26) list two ways to increase the strength of an electromagnet. 27) the wire in a simple motor feels a force when a current flows through it. why is this? i need answers to check mine

Paul and ivan are riding a tandem bike together. they’re moving at a speed of 5 meters/second. paul and ivan each have a mass of 50 kilograms. what can paul do to increase the bike’s kinetic energy?