A parachutist jumping from an airplane reaches a terminal velocity when the force of air resistance is 980 N. Find the mass of the parachutist.

Suppose that a comet that was seen in 563 a.d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up

The velocity of a car traveling in a straight line increases from 0 meters/second to 30meters/second in 8 seconds. what is the average acceleration of the car?