Question

When a car driving up a hill with constant speed: I. its kinetic energy is decreasing. II. its potential energy is constant. III. its total mechanical energy is constant. Group of answer choices II I III none of the above

Answer 1

A car driving up a hill at a constant speed experiences no change in its kinetic energy while it's potential energy increases with increasing height, thus none of the options are correct.

Understanding the concept

Consider a car moving up the hill at a constant speed as shown in the figure below. The following forces act on the car:

• N is the normal reaction force acting in an upward direction

• f_s is the static friction force exerted due to friction between the road and the tires of the car
• f_k is the rolling friction force in the direction opposing that of the  tire
• mg is the force acting in a downward direction.

• θ is the angle of inclination.

Here as the car is moving up the hill at a constant speed, the net force exerted on the car is zero. Also, the kinetic energy of the car will not change as its velocity is constant and the potential energy will change with increasing height. Thus, none of the given options are correct.

Learn more about motion on an incline here:

brainly.com/question/13513083

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