Question 1

An astronaut in an orbiting space-craft feels "weightless" because she:

Accepted Answer

A)  is beyond the range of gravity 
B)  is pulled outwards by centrifugal force 
C)  has no acceleration 
D)  has the same acceleration as the space-craft 
E)  is outside Earth's atmosphere 
A)  is beyond the range of gravity 
B)  is pulled outwards by centrifugal force 
C)  has no acceleration 
D)  has the same acceleration as the space-craft 
E)  is outside Earth's atmosphere D

Question 2

A small satellite is in elliptical orbit around Earth as shown. If L denotes the magnitude of its angular momentum and K denotes kinetic energy:

Accepted Answer

A)  L2 > L1 and K2 > K1 
B)  L2 > L1 and K2 = K1 
C)  L2 = L1 and K2 = K1 
D)  L2 1 and K2 = K1 
E)  L2 = L1 and K2 > K1 
A)  L2 > L1 and K2 > K1 
B)  L2 > L1 and K2 = K1 
C)  L2 = L1 and K2 = K1 
D)  L2 1 and K2 = K1 
E)  L2 = L1 and K2 > K1 E

Question 3

The mass density of a certain planet has spherical symmetry but varies in such a way that the mass inside every spherical surface with center at the center of the planet is proportional to the radius of the surface. If r is the distance from the center of the planet to a point mass inside the planet, the gravitational force on the mass is:

Accepted Answer

A)  not dependent on r 
B)  proportional to r2 
C)  proportional to r 
D)  proportional to 1/r 
E)  proportional to 1/r2 
A)  not dependent on r 
B)  proportional to r2 
C)  proportional to r 
D)  proportional to 1/r 
E)  proportional to 1/r2 D

Question 4

An object is raised from the surface of Earth to a height of two Earth radii above Earth. Then:

Accepted Answer

A)  its mass increases and its weight remains constant 
B)  both its mass and weight remain constant 
C)  its mass remains constant and its weight decreases 
D)  both its mass and its weight decrease 
E)  its mass remains constant and its weight increases 
A)  its mass increases and its weight remains constant 
B)  both its mass and weight remain constant 
C)  its mass remains constant and its weight decreases 
D)  both its mass and its weight decrease 
E)  its mass remains constant and its weight increases

Question 5

Let F1 be the magnitude of the gravitational force exerted on the Sun by Earth and F2 be the magnitude of the force exerted on Earth by the Sun. Then:

Accepted Answer

A)  F1 is much greater than F2 
B)  F1 is slightly greater than F2 
C)  F1 is equal to F2 
D)  F1 is slightly less than F2 
E)  F1 is much less than F2 
A)  F1 is much greater than F2 
B)  F1 is slightly greater than F2 
C)  F1 is equal to F2 
D)  F1 is slightly less than F2 
E)  F1 is much less than F2

Question 6

For a planet in orbit around a star the perihelion distance is rp and its speed at perihelion is vp. The aphelion distance is ra and its speed at aphelion is va. Which of following is true?

Accepted Answer

A)  va = vp 
B)  va/ ra = vp/rp 
C)  va ra = vp rp 
D)  va/ r2a = vp/r2p 
E)  va r2a = vp/r2p 
A)  va = vp 
B)  va/ ra = vp/rp 
C)  va ra = vp rp 
D)  va/ r2a = vp/r2p 
E)  va r2a = vp/r2p

Question 7

Neglecting air resistance, the escape speed from a certain planet for an empty space vehicle is 1.12 *104 m/s. What is the corresponding escape speed for the fully loaded vehicle which has triple the mass of the empty one?

Accepted Answer

A)  3.73 * 103 m/s 
B)  1.12* 104 m/s 
C)  3.36 * 104 m/s 
D)  9.98 * 104 m/s 
E)  1.40 * 1012 m/s 
A)  3.73 * 103 m/s 
B)  1.12* 104 m/s 
C)  3.36 * 104 m/s 
D)  9.98 * 104 m/s 
E)  1.40 * 1012 m/s

Question 8

In the formula F = Gm1m2/r2, the quantity G:

Accepted Answer

A)  depends on the local value of g 
B)  is used only when the Earth is one of the two masses 
C)  is greatest at the surface of the Earth 
D)  is a universal constant of nature 
E)  is related to the Sun in the same way that g is related to the Earth 
A)  depends on the local value of g 
B)  is used only when the Earth is one of the two masses 
C)  is greatest at the surface of the Earth 
D)  is a universal constant of nature 
E)  is related to the Sun in the same way that g is related to the Earth

Question 9

Given the perihelion distance, aphelion distance, and speed at perihelion of a planet, which of the following CANNOT be calculated?

Accepted Answer

A)  the mass of the star 
B)  the mass of the planet 
C)  the speed of the planet at aphelion 
D)  the period of orbit 
E)  the semimajor axis of the orbit 
A)  the mass of the star 
B)  the mass of the planet 
C)  the speed of the planet at aphelion 
D)  the period of orbit 
E)  the semimajor axis of the orbit

Question 10

A particle might be placed   Rank these situations according to the magnitude of the gravitational force on the particle, least to greatest.

Accepted Answer

A)  All tie 
B)  1, 2, 3, 4 
C)  1 and 2 tie, then 3 and 4 tie 
D)  1 and 2 tie, then 3, then 4 
E)  1 and 2 tie, then 4, then 3 
A)  All tie 
B)  1, 2, 3, 4 
C)  1 and 2 tie, then 3 and 4 tie 
D)  1 and 2 tie, then 3, then 4 
E)  1 and 2 tie, then 4, then 3

Question 11

Venus has a mass of about 0.0558 times the mass of Earth and a diameter of about 0.381 times the diameter of Earth. The acceleration of a body falling near the surface of Venus is about:

Accepted Answer

A)  0.21 m/s2 
B)  1.4 m/s2 
C)  2.8 m/s2 
D)  3.8 m/s2 
E)  25 m/s2 
A)  0.21 m/s2 
B)  1.4 m/s2 
C)  2.8 m/s2 
D)  3.8 m/s2 
E)  25 m/s2

Question 12

A planet is in circular orbit around the Sun. Its distance from the Sun is four times the average distance of Earth from the Sun. The period of this planet, in Earth years, is:

Accepted Answer

A)  4 
B)  8 
C)  16 
D)  64 
E)  2.52 
A)  4 
B)  8 
C)  16 
D)  64 
E)  2.52

Question 13

Let M denote the mass of Earth and let R denote its radius. The ratio g/G at Earth's surface is:

Accepted Answer

A)  R2/M 
B)  M/R2 
C)  MR2 
D)  M/R 
E)  R/M 
A)  R2/M 
B)  M/R2 
C)  MR2 
D)  M/R 
E)  R/M

Question 14

Four particles, each with mass m, are arranged symmetrically about the origin on the x axis. A fifth particle, with mass M, is on the y axis. The direction of the gravitational force on M is:

Accepted Answer

A)  $\uparrow$ 
B)  $\downarrow$ 
C)  $\leftarrow$ 
D)  $\rightarrow$ 
E)  none of these directions 
A)  $\uparrow$ 
B)  $\downarrow$ 
C)  $\leftarrow$ 
D)  $\rightarrow$ 
E)  none of these directions

Question 15

A planet in another solar system orbits a star with a mass of 4.0 * 1030 kg. At one point in its orbit it is 250 *106 km from the star and is moving at 35 km/s. Take the universal gravitational constant to be 6.67 *10-11 m2/s2 . kg and calculate the semimajor axis of the planet's orbit. The result is:

Accepted Answer

A)  79 *106 km 
B)  160 * 106 km 
C)  240 * 106 km 
D)  320 * 106 km 
E)  590 * 106 km 
A)  79 *106 km 
B)  160 * 106 km 
C)  240 * 106 km 
D)  320 * 106 km 
E)  590 * 106 km

Question 16

A planet travels in an elliptical orbit about a star as shown. At what pair of points is the speed of the planet the same?

Accepted Answer

A)  W and S 
B)  P and T 
C)  P and R 
D)  Q and U 
E)  Vand R 
A)  W and S 
B)  P and T 
C)  P and R 
D)  Q and U 
E)  Vand R

Question 17

A spaceship is returning to Earth with its engine turned off. Consider only the gravitational field of Earth and let M be the mass of Earth, m be the mass of the spaceship, and R be the distance from the center of Earth. In moving from position 1 to position 2 the kinetic energy of the spaceship increases by:

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 18

The speed of a comet in an elliptical orbit about the sun:

Accepted Answer

A)  decreases while it is receding from the sun 
B)  is constant 
C)  is greatest when farthest from the sun 
D)  varies sinusoidally with time 
E)  equals L/(mr), where L is its angular momentum, m is its mass, and r is its distance from the sun 
A)  decreases while it is receding from the sun 
B)  is constant 
C)  is greatest when farthest from the sun 
D)  varies sinusoidally with time 
E)  equals L/(mr), where L is its angular momentum, m is its mass, and r is its distance from the sun

Question 19

An astronaut finishes some work on the outside of his satellite, which is in circular orbit around the Earth. He leaves his wrench outside the satellite. The wrench will:

Accepted Answer

A)  fall directly down to the Earth 
B)  continue in orbit at reduced speed 
C)  continue in orbit with the satellite 
D)  fly off tangentially into space 
E)  spiral down to the Earth 
A)  fall directly down to the Earth 
B)  continue in orbit at reduced speed 
C)  continue in orbit with the satellite 
D)  fly off tangentially into space 
E)  spiral down to the Earth

Question 20

Of the following where would the weight of an object be the least?

Accepted Answer

A)  2000 miles above Earth's surface 
B)  At the north pole 
C)  At the equator 
D)  At the center of Earth 
E)  At the south pole 
A)  2000 miles above Earth's surface 
B)  At the north pole 
C)  At the equator 
D)  At the center of Earth 
E)  At the south pole

Exam 13: Gravitation

An astronaut in an orbiting space-craft feels "weightless" because she:

A small satellite is in elliptical orbit around Earth as shown. If L denotes the magnitude of its angular momentum and K denotes kinetic energy:

An object is raised from the surface of Earth to a height of two Earth radii above Earth. Then:

Let F1 be the magnitude of the gravitational force exerted on the Sun by Earth and F2 be the magnitude of the force exerted on Earth by the Sun. Then:

For a planet in orbit around a star the perihelion distance is rp and its speed at perihelion is vp. The aphelion distance is ra and its speed at aphelion is va. Which of following is true?

Neglecting air resistance, the escape speed from a certain planet for an empty space vehicle is 1.12 *104 m/s. What is the corresponding escape speed for the fully loaded vehicle which has triple the mass of the empty one?

In the formula F = Gm1m2/r2, the quantity G:

Given the perihelion distance, aphelion distance, and speed at perihelion of a planet, which of the following CANNOT be calculated?

A particle might be placed Rank these situations according to the magnitude of the gravitational force on the particle, least to greatest.

Venus has a mass of about 0.0558 times the mass of Earth and a diameter of about 0.381 times the diameter of Earth. The acceleration of a body falling near the surface of Venus is about:

A planet is in circular orbit around the Sun. Its distance from the Sun is four times the average distance of Earth from the Sun. The period of this planet, in Earth years, is:

Let M denote the mass of Earth and let R denote its radius. The ratio g/G at Earth's surface is:

Four particles, each with mass m, are arranged symmetrically about the origin on the x axis. A fifth particle, with mass M, is on the y axis. The direction of the gravitational force on M is:

A planet travels in an elliptical orbit about a star as shown. At what pair of points is the speed of the planet the same?

The speed of a comet in an elliptical orbit about the sun:

An astronaut finishes some work on the outside of his satellite, which is in circular orbit around the Earth. He leaves his wrench outside the satellite. The wrench will:

Of the following where would the weight of an object be the least?

Measurement

Motion Along a Straight Line

Vector

Motion in Two and Three Dimensions

Force and Motion I

Force and Motion II

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Fluids

Oscillations

Waves I

Waves II

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Electric Charge

Electric Fields

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Nuclear Physics

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

Let F₁ be the magnitude of the gravitational force exerted on the Sun by Earth and F₂ be the magnitude of the force exerted on Earth by the Sun. Then:

For a planet in orbit around a star the perihelion distance is r_p and its speed at perihelion is v_p. The aphelion distance is r_a and its speed at aphelion is v_a. Which of following is true?

Neglecting air resistance, the escape speed from a certain planet for an empty space vehicle is 1.12 *10⁴ m/s. What is the corresponding escape speed for the fully loaded vehicle which has triple the mass of the empty one?

In the formula F = Gm₁m₂/r², the quantity G: