Gravitational fields Flashcards
1
Q
Why do astronauts in orbital space feel a sense of weightlessness
A
The astronaut and space shuttle travel at the same orbital speed
There is no normal reaction between vehicle and astronaut
2
Q
Explain how to rotation of the earth affects the reading on the bathroom scale?
A
- apparent weight would decrease
- some gravitational force provides the necessary centripetal force
3
Q
Why is potential energy negative?
A
There is zero potential at infinity
Work is done to move to infinity from a point, so potential energy falls as an object moves closer to infinity
4
Q
What is the effect on the values of Ep and V if mass is double
A
GPE would double
V - unchanged
5
Q
Why do some objects not have a circular orbit
A
The resultant force is not centripetally directed to the centre of the object they’re orbiting
