Anyone help me please

Aparticle travels in a circular orbit of radius 21 m. its speed is changing at a rate of 23.1 m/s2 at an instant when its speed is 37.2 m/s. what is the magnitude of the acceleration (in m/s? ) of the particle?

Afigure skater is rotating at a rate of 200 revolutions per minute. what is the angular speed, in units of rad/s? 20.9 12000 200 3.33

How many neutrons does plutonium -196 with an atomic number of 78.