IB Fields AHL

page 1

 

1. The gravitational potential at the Earth's surface is about -60 MJ kg-1 . The work done in lifting a 2kg mass into deep space away from the Earth is therefore

  • A. +60MJ
  • B. -60 MJ
  • C. +120MJ
  • D. -120MJ

2. A planet that is twice as massive as the Earth but only has 1/2 the radius will therefore have a gravitational potential at the surface of about

  • A. -15 MJ kg-1
  • B. -60 MJ kg-1
  • C. -120 MJ kg-1
  • D. -240 MJ kg-1

3. Which of these statements about the magnitude of the gravitational field strength at any point is true?

  • A. gravitational field strength = gravitational potential gradient
  • B. gravitational field strength = gravitational force gradient
  • C. gravitational field strength gradient = gravitational potential
  • D. gravitational field strength gradient = gravitational force

 

4. Which of these diagrams shows the shape of equipotential surfaces around two identical binary stars?

 

Two small masses m and 2m are located at distances r and 2r from a much larger planet as shown.

 

 

5. The ratio

gravitational potential at m
gravitational potential at 2m

is

  • A. 2
  • B. 1/2
  • C. 4
  • D. 1/4

6. To escape the pull of a small spherical asteroid, a satellite needs to be launched with a certain escape velocity. Which of these 3 factors affects the escape velocity of the satellite?

I
The mass of the asteroid.
II
The mass of the satellite.
III
The radius of the asteroid.

 

image:

nasa.gov

  • A. I and II
  • B. I and III
  • C. II and III
  • D. All three statements
 

7. To stay in a circular orbit of radius r around the Earth, a satellite of mass m has a potential energy of Ep. If the satellite now moves into a higher orbit of radius 2r, the potential energy..

A. increases by
GMm
r
B. decreases by
GMm
r
C. increases by
GMm
2r
D. decreases by
GMm
2r

 

8. When in orbit, how is the gravitational potential energy (Ep) of a satellite related to the kinetic energy (Ek)?

  • A. Ep= Ek
  • B. Ep= 2Ek
  • C. Ep = - Ek
  • D. Ep = - 2Ek

9. As the satellite moves into a higher orbit, how does the total energy and the kinetic energy change?

total energy
kinetic energy
A
increases
decreases
B
increases
increases
C
decreases
constant
D
decreases
decreases