Once he reach the bottom of the hill he slides across the ground horizontal. it takes him 20 seconds to slow down from his speed at the bottom of the hill to stop what is his acceleration when he sliding horizontally?

Red light strikes a metal surface and electrons are ejected. if violet light is now used with a 10% greater intensity, what will happen to the ejection rate (number of ejected electrons per second) and the maximum energy of the electrons? a) greater ejection rate; same maximum energyb) same ejection rate; greater maximum energyc) greater ejection rate; greater maximum energyd) same ejection rate; same maximum energye) none of the above answers are correct

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?