17. What is the gain in gravitational potential energy of a body of weight 2000 N as it rises from a height of 20 m to a height of 25 m above the earth's surface? (A) 400 J
(B) 1 000 J
(C) 10 000 J
(D) 20 000 J​

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.