Kinetic Energy Calculation Example

What is the kinetic energy of a bicycle and its rider travelling at a speed of 18 km/h with a mass of 73 kg?

A. 1.2×10^4 J

B. 1.3×10^3 J

C. 9.1×10^2 J

D. 7.3×10^18 J

Final answer:

The kinetic energy of the bicycle and its rider, calculated using the mass and speed given in the problem, comes out to be approximately 1.2×10^4 J, option A in the question.

Explanation:

The kinetic energy of an object can be calculated using the formula: KE = 0.5 * m * v^2. Where 'm' is the mass of the object (in this case, the bicycle and rider) and 'v' is the speed.

Given that the mass is 73 kg and the speed is 18 km/h (which needs to be converted to m/s for calculation by dividing by 3.6), we have:

KE = 0.5 * 73 kg * (18 km/h / 3.6)^2.

After calculation, the kinetic energy in joules is approximately 1.2×10^4 J. Therefore, the correct answer is A. 1.2×10^4 J.