Title: Description Questions
Course: Physics copy 1

Q: [Image: vector matching quesiton]

An elevator car and rider are shown in the image above. The system is free moving. The car is accelerating upwards. Match each vector number with its appropriate description.
- $$\vec F_g$$ (force of gravity) | 1
- $$\vec F_{net}$$ (net force) | 2
- $$\vec F_t$$ (force of tension) | 3

Q: [Image: elevator and rider labelled]
An elevator car and rider are shown in the system above. It is accelerating upwards. The force of the tension can be calculated as $$\vec F_t=\vec F_{net}- \vec F_g$$. Consider up to be positive in this frame of reference).
- True (Thats right. You have to remember that $$\vec F_g$$ is directed downwards, and so changes direction when its subtracted.)
- False (No. This is true. Make sure you understand vector addition and subtraction)
A: True

[Image: trolley car toy] |

To find the acceleration of connected bodies, it is usually beneficial to find the net force on the entire system and then divide by the system mass (Newtons second law) to find the acceleration. It is often beneficial when solving for tension to deal with only one body after the acceleration is known.

To find the acceleration of connected bodies, it is usually beneficial to find the net force on the entire system, then divide by the system mass to find the acceleration. It is often beneficial when solving for tension to deal with only one body after the acceleration is known. |