The speed of a car is increased uniformly from 20. meters per second to 30. meters per second towards the right in 4.0 seconds. The magnitude of the car's average
acceleration in this 4.0-second interval is

A 13m/s2

B 2.5m/s2

C 10m/s2

D 0.40m/s2

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

Observations show that interstellar clouds can have almost any shape and

When electrons are added to the outermost shell of a carbon atom, it forms--an anion that has a larger anion that has a smaller cation that has a larger cation that has a smaller radius.