Question

Which of the following statements is incorrect?

• A. Kinetic energy may be zero, positive or negative
• B. Power, energy and work are all scalars
• C. Potential energy may be zero, positive or negative
• D. Ballistic pendulum is a device for measuring the speed of bullets

Answer 1

Answer: (A)

Kinetic energy may be zero, positive or negative

Answer 2

If an object of mass m moving with velocity , its kinetic energy k is given by

As mass m and are always positive, therefore kinetic energy is always positive. The kinetic energy can never by negative.