Question

What work is said to be done to increase the velocity of a car from 15 km/h to 30 km/h, if the mass of the car is 1000 kg?

Answer 1

Answer:

physics, the kinetic energy (KE) of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.

Answer 2

Answer:

8652.8 J

Explanation:

For this question,

Work done = Kinetic energy applied

Given that,

Initial velocity, u = 15 km/h = 4.16 m/s

Final velocity, v = 30 km/h = 8.32 m/s

Mass, m = 1000 kg

Kinetic energy applied = $\frac{1}{2}$ × mass × (change in velocity)²

or, K.E. = $\frac{1}{2}$ × m × (v-u)²

= $\frac{1}{2}$ × 1000 kg × (8.32 - 4.16 m/s)²

= 500 kg × (4.16 m/s)²

= 500 kg × 17.3 m²/s²

= 8652.8 kg.m²/s²

= 8652.8 J