Respuesta :

Answer:

  1. The total kinetic energy before accelerating = 750 J
  2. The total kinetic energy after accelerating = 3,000 J
  3. Total work done = 2,250 J

Explanation:

Given:

Mass of bicyclist = 50 kg

Mass of bicycle = 10 kg

Initial velocity (u) = 5 m/s

Final velocity (v) = 10 m/s

Find:

(a) What was the total kinetic energy before accelerating = ?

(b) What was the total kinetic energy after accelerating = ?

(c) How much work was done to increase the kinetic energy of the bicyclist = ?

Computation:

Total mass (M) = 50 kg + 10 kg = 60 kg

1. The total kinetic energy before accelerating = 1/2[Mu²]

The total kinetic energy before accelerating = 0.5[(60)(5)²]

The total kinetic energy before accelerating = 750 J

2. The total kinetic energy after accelerating = 1/2[Mv²]

The total kinetic energy after accelerating = 0.5[(60)(10)²]

The total kinetic energy after accelerating = 3,000 J

3. Total work done = Δ K.E

Total work done = 3,000 J - 750 J

Total work done = 2,250 J