A powered camera carriage moves east along a straight, horizontal rail.
The carriage has a mass of 75 kg. The only horizontal forces on it are a constant force from the motor acting east and a cable force of 40 N acting west.
The velocity of the carriage is recorded.
| Time / s\text{s}s | Velocity east / m s−1\text{m s}^{-1}m s−1 |
|---|---|
| 0 | 1.2 |
| 3.0 | 3.6 |
Calculate the force exerted by the motor on the carriage.
Later, while the carriage is still moving east, the motor force decreases to 25 N east. The cable force remains at 40 N west and both forces then remain constant.
Describe the subsequent motion of the carriage.