5kg of copper ball and I kg of water are at the same temperature of 31 C. Which substance loses more heat energy, when both of them are cooled upto 30°C​

What sort of waves exhibit the doppler effect?

Robin is swinging back and forth from a trapeze. in which of the following situations is his kinetic energy being transformed into potential energy

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