A 20 kg sled stars at the top of a hill which is 10 m above the bottom and slides a distance of 50 m, ending at the bottom of the hill with a speed of 8 m/s. During the slide, the work done by gravity is about

80 Joules.

Explanation:

Given that a 20 kg sled stars at the top of a hill which is 10 m above the bottom and slides a distance of 50 m, ending at the bottom of the hill with a speed of 8 m/s. During the slide, the work done by gravity is about ?

The parameters given are:

Mass M = 20 kg

Height h = 10 m

Velocity V = 8 m/s

The workdone by gravity will be equal to the total energy

At the bottom of the hill, the total energy will be equal to the maximum kinetic energy.

Maximum K.E = 1/2mv^2

K.E = 1/2 × 20 × 8

K.E = 80J

Therefore, the workdone by the gravity is equal to 80 Joules.

c.the charges if the proton and electron and gravity

the answer is b, have negligible mass