There are grooves on the surface of tyres. Why?

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

What are the starting materials for nuclear fission? two small nuclei two large nuclei a neutron and a large nucleus a neutron and a small nucleus

When using the scientist method, which step comes last?