A3 kg penguin is pushed by his penguin friends who give him an initial speed vo at the top of a 30 m hill. the penguin is hoping this will be enough initial speed that he can make it all the way down this hill and up the next hill which is 45 m tall. neglecting friction and air resistance, what does the initial speed need to be for him to make it up this second hill?

State one advantage and one disadvantage of using a plane mirrior as a driving mirrior

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Acoil suspended freely, points in some direction when no current is passed through it . can you tell what will happen when a current is passed though it?