A machine performs 8 Joules of work in 2 seconds. How much power is delivered by this machine?

Q1; Multiple Choice: If the distance between two objects, each of mass 'M', is tripled, the force of attraction between the two objects is:
w) 1/2 the original force
x) 1/3 the original force
y) 1/9 the original force
z) unchanged
ANSWER: Y -- 1/9 THE ORIGINAL FORCE

Q2; Short Answer: A 40 kilogram girl climbs a vertical distance of 5 meters in twenty seconds at a constant velocity. How much work has the girl done?
ANSWER: 2000 JOULES or 1960 JOULES

Q3; Short Answer: A machine performs 8 Joules of work in 2 seconds. How much power is delivered by this machine?
ANSWER: 4 WATTS

Q4; Multiple Choice: In physics, a radian per second is a unit of:
w) angular displacement
x) angular velocity
y) angular acceleration
z) angular momentum.
ANSWER: X -- ANGULAR VELOCITY

Q5; Multiple Choice: If the resultant force acting on a body of constant mass is zero, the body's momentum is:
w) increasing
x) decreasing
y) always zero
z) constant
ANSWER: Z -- CONSTANT