Studied by 0 peopleWhat is a force field?
What do the arrows on gravitational field lines represent?
The direction of the force on a test mass at that point in a gravitational field.
Sketch how gravitational field lines might look in a radial field
Sketch how gravitational field lines might look on the Earth’s surface
When can E(p) = mgh only be used?
In scenarios where g is constant in a uniform gravitational field.
Is the gravitational potential positive or negative when an object is moving from point infinity (zero potential) to a point?
Negative potential as negative work is done on the object (as gravitational forces are attractive) moving it from infinity to that point.
This work is done by the gravitational field on test mass.
What is the potential of an object moving it from a point to infinity?
It is a positive potential as positive work is done on the object moving if from the point to infinity.
This positive work is done on the test mass against the gravitational force.
What is gravitational potential?
Work done per unit mass moving an object from infinity to a point.
Use W = mV (rearranged)
What is the potential at point infinity?
0
What is gravitational potential energy?
The work done moving an object form infinity to a point.
What is escape velocity?
The minimum speed an unpowered object (ballistic) needs to have to leave a planet & not fall back due to gravitational attraction.
Derive escape velocity?
Draw a graph of g against r? What does its area represent?
Area - change in gravitational potential
Draw a graph of V against r? What does the gradient represent?
Gradient - gravitational field strength
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