Which of the following sets of equipment cannot be used to measure the local value of the acceleration due to gravity (g) ?
Answer Choices
A. A spring scale (which reads in force units) and a known mass.
B. A rod of known length, an unknown mass, and a stopwatch.
C. An inclined plane of known inclination, several carts of different known masses, and a stopwatch.
D. A launcher which launches projectiles at a known speed, a projectile of known mass, and a meter stick.
E. A motor with a known output power, a known mass, a piece of string of unknown length, and a stopwatch.