Gravity Flashcards
(9 cards)
1
Q
GPE
A
Energy of an object due to its position in a gravitational field
Zero GPE at infinity
Rocket must increase GPE to zero to escape planet fields
2
Q
Gravitational Potential
A
Work done per unit mass to move a small object from infinity to that point
3
Q
V=?
A
V= WD/mass
4
Q
Work done to escape plant fields
A
WD = mV
5
Q
Potential gradient
A
Change in potential per metre at a point
6
Q
Potential gradient equation
A
PG = ^V/^r
r is small distance
7
Q
Gravitational field strength
A
The force per unit mass of a small test mass placed in a field
g= F/m
8
Q
Newton’s law of gravitation
A
- always attractive
- proportional to mass
- proportional to 1/r^2 (r = dist. apart)
F= GMm/r^2
9
Q
Escape velocity
A
Minimum velocity to escape a planet when projected vertically from surface
