at a track and field meet, the best long jump is 8m. the jumper took off an angle of 31 degrees to horizontal. what was the initial speed

Which sentences describe disadvantages of burning fossil fuels instead of using hydrogen fuel cells? burning fossil fuels contributes to climate change. burning fossil fuels takes place inside expensive fuel cells. fossil fuels aren't widely available, but pure hydrogen is. fossil fuels are nonrenewable.

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?