Question 1

Two moons orbit a planet in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

Accepted Answer

A)  20 d 
B)  40 d 
C)  80 d 
D)  160 d 
E)  320 d

Question 2

Three identical very small 50-kg masses are held at the corners of an equilateral triangle, 0.30 m on each side. If one of the masses is released, what is its initial acceleration if the only forces acting on it are the gravitational forces due to the other two masses? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A)  3.7 × 10-8 m/s2 
B)  2.5 × 10-8 m/s2 
C)  1.9 × 10-8 m/s2 
D)  4.2 × 10-8 m/s2 
E)  6.4 × 10-8 m/s2

Question 3

A very small round ball is located near a large solid sphere of uniform density. The force that the large sphere exerts on the ball

Accepted Answer

A)  is exactly the same as it would be if all the mass of the sphere were concentrated at the center of the sphere. 
B)  is approximately the same as it would be if all the mass of the sphere were concentrated at the center of the sphere. 
C)  is independent of the mass of the ball. 
D)  is independent of the mass of the sphere. 
E)  can only be calculated using calculus.

Question 4

Ekapluto is an unknown planet that has two moons in circular orbits. The table summarizes the hypothetical data about the moons. (G = 6.67 × 10-11 N ∙ m2/kg2)  The mass of Ekapluto is closest to

Accepted Answer

A)  1.0 × 1022 kg. 
B)  3.0 × 1022 kg. 
C)  1.0 × 1023 kg. 
D)  3.0 × 1023 kg. 
E)  1.0 × 1024 kg.

Question 5

Neptune circles the Sun at a distance of 4.50 × 1012 m once every 164 years. Saturn circles the Sun at a distance of 1.43 x 1012 m. What is the orbital period of Saturn?

Accepted Answer

A)  304 y 
B)  121 y 
C)  109 h 
D)  88.6 y 
E)  29.4 y

Question 6

A small-sized 155-kg mass is located 1.50 m from a small-sized 275-kg mass, with both masses fixed in place. Where should you place a third small-sized mass so that the net gravitational force on it due to the original two masses is zero?

Accepted Answer

The answer of A small-sized 155-kg mass is located 1.50...

Question 7

If the mass of the earth and all objects on it were suddenly doubled, but the size remained the same, the acceleration due to gravity at the surface would become

Accepted Answer

A)  4 times what it now is. 
B)  2 times what it now is. 
C)  the same as it now is. 
D)  1/2 of what it now is. 
E)  1/4 of what it now is.

Question 8

A certain planet has an escape speed V. If another planet has twice size and twice the mass of the first planet, its escape speed will be

Accepted Answer

A)  2V. 
B)   V. 
C)  V. 
D)  V/2. 
E)  V/  .

Question 9

A satellite that weighs 4900 N on the launchpad travels around the earth's equator in a circular orbit with a period of 1.667 h. The earth's mass is 5.97 × 10²⁴ kg, its equatorial radius is 6.3 × 10⁶ m, and G = 6.67 × 10^-11 N ∙ m²/kg². (a) Calculate the magnitude of the earth's gravitational force on the satellite. (b) Determine the altitude of the satellite above the Earth's SURFACE.

Accepted Answer

The answer of A satellite that weighs 4900 N on...

Question 10

The reason an astronaut in an earth satellite feels weightless is that

Accepted Answer

A)  the astronaut is beyond the range of the earth's gravity. 
B)  the astronaut is falling. 
C)  the astronaut is at a point in space where the effects of the moon's gravity and the earth's gravity cancel. 
D)  this is a psychological effect associated with rapid motion. 
E)  the astronaut's acceleration is zero.

Question 11

A huge cannon is assembled on an airless planet having insignificant axial spin. The planet has a radius of 5.00 × 106 m and a mass of 3.95 × 1023 kg. The cannon fires a projectile straight up at 2000 m/s. An observation satellite orbits the planet at a height of 1000 km. What is the projectile's speed as it passes the satellite? (G = 6.67 × 10-11 N ∙ m2/kg2)

Accepted Answer

A)  1500 m/s 
B)  1380 m/s 
C)  1610 m/s 
D)  1280 m/s

Question 12

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 106 m, G = 6.67 × 10-11 N ∙ m2/kg2.)

Accepted Answer

A)  -0.60 N 
B)  -1.5 N 
C)  -2.6 N 
D)  -3.6 N 
E)  -5.2 N

Question 13

The International Space Station is orbiting at an altitude of about 370 km above the earth's surface. The mass of the earth is 5.97 × 10²⁴ kg, the radius of the earth is 6.38 × 10⁶ m, and G = 6.67 × 10^-11 N ∙ m²/kg². Assuming a circular orbit, (a) what is the period of the International Space Station's orbit? (b) what is the speed of the International Space Station in its orbit?

Accepted Answer

The answer of The International Space Station is orbiting at...

Question 14

A satellite is in circular orbit at an altitude of 1500 km above the surface of a nonrotating planet with an orbital speed of 9.2 km/s. The minimum speed needed to escape from the surface of the planet is 14.9 km/s, and G = 6.67 × 10-11 N ∙ m2/kg2. The orbital period of the satellite is closest to

Accepted Answer

A)  72 min. 
B)  65 min. 
C)  58 min. 
D)  51 min. 
E)  44 min.

Question 15

Planet Z-34 has a mass equal to 1/3 that of Earth, a radius equal to 1/3 that of Earth, and an axial spin rate 1/2 that of Earth. With g representing, as usual, the acceleration due to gravity on the surface of Earth, the acceleration due to gravity on the surface of Z-34 is

Accepted Answer

A)  g/3. 
B)  3g. 
C)  6g. 
D)  g/9. 
E)  9g.

Question 16

What is the ratio of the escape speed of a rocket launched from sea level to the escape speed of one launched from Mt. Everest (an altitude of 8.85 km)? The radius of the earth is 6.38 × 106 m.

Accepted Answer

A)  1.0007 
B)  1.0014 
C)  1.0001 
D)  0.9986 
E)  0.9993

Question 17

A meteoroid, heading straight for Earth, has a speed of 14.8 km/s relative to the center of Earth as it crosses our moon's orbit, a distance of 3.84 × 108 m from the earth's center. What is the meteroid's speed as it hits the earth? You can neglect the effects of the moon, Earth's atmosphere, and any motion of the earth. (G = 6.67 × 10-11 N ∙ m2/kg2, Mearth = 5.97 × 1024 kg)

Accepted Answer

A)  18.5 km/s 
B)  21.5 km/s 
C)  32.4 km/s 
D)  87.3 km/s

Question 18

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.9200g? The radius of the earth is 6.38 × 106 m.

Accepted Answer

A)  272 km 
B)  260 km 
C)  554 km 
D)  510 km

Question 19

An astronaut is in equilibrium when he is positioned 140 km from the center of asteroid X and 581 km from the center of asteroid Y, along the straight line joining the centers of the asteroids. What is the ratio of the masses X/Y of the asteroids?

Accepted Answer

A)  0.0581 
B)  17.2 
C)  0.241 
D)  4.15

Question 20

A planet has two small satellites in circular orbits around the planet. The first satellite has a period 12.0 hours and an orbital radius 6.00 × 107 m. The second planet has a period 16.0 hours. What is the orbital radius of the second satellite?

Accepted Answer

A)  4.50 × 107 
B)  3.90 × 107 
C)  9.24 × 107 
D)  8.00 × 107 
E)  7.27 × 107

Exam 13: Newtons Theory of Gravity

Two moons orbit a planet in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

A very small round ball is located near a large solid sphere of uniform density. The force that the large sphere exerts on the ball

Ekapluto is an unknown planet that has two moons in circular orbits. The table summarizes the hypothetical data about the moons. (G = 6.67 × 10^-11 N ∙ m²/kg²) The mass of Ekapluto is closest to

Neptune circles the Sun at a distance of 4.50 × 10¹² m once every 164 years. Saturn circles the Sun at a distance of 1.43 x 10¹² m. What is the orbital period of Saturn?

A small-sized 155-kg mass is located 1.50 m from a small-sized 275-kg mass, with both masses fixed in place. Where should you place a third small-sized mass so that the net gravitational force on it due to the original two masses is zero?

If the mass of the earth and all objects on it were suddenly doubled, but the size remained the same, the acceleration due to gravity at the surface would become

A certain planet has an escape speed V. If another planet has twice size and twice the mass of the first planet, its escape speed will be

The reason an astronaut in an earth satellite feels weightless is that

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 10⁶ m, G = 6.67 × 10^-11 N ∙ m²/kg².)

Planet Z-34 has a mass equal to 1/3 that of Earth, a radius equal to 1/3 that of Earth, and an axial spin rate 1/2 that of Earth. With g representing, as usual, the acceleration due to gravity on the surface of Earth, the acceleration due to gravity on the surface of Z-34 is

What is the ratio of the escape speed of a rocket launched from sea level to the escape speed of one launched from Mt. Everest (an altitude of 8.85 km) ? The radius of the earth is 6.38 × 10⁶ m.

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.9200g? The radius of the earth is 6.38 × 10⁶ m.

An astronaut is in equilibrium when he is positioned 140 km from the center of asteroid X and 581 km from the center of asteroid Y, along the straight line joining the centers of the asteroids. What is the ratio of the masses X/Y of the asteroids?

A planet has two small satellites in circular orbits around the planet. The first satellite has a period 12.0 hours and an orbital radius 6.00 × 10⁷ m. The second planet has a period 16.0 hours. What is the orbital radius of the second satellite?

Exam 13: Newtons Theory of Gravity

Two moons orbit a planet in nearly circular orbits. Moon A has orbital radius r, and moon B has orbital radius 4r. Moon A takes 20 days to complete one orbit. How long does it take moon B to complete an orbit?

A very small round ball is located near a large solid sphere of uniform density. The force that the large sphere exerts on the ball

Ekapluto is an unknown planet that has two moons in circular orbits. The table summarizes the hypothetical data about the moons. (G = 6.67 × 10-11 N ∙ m2/kg2) The mass of Ekapluto is closest to

Neptune circles the Sun at a distance of 4.50 × 1012 m once every 164 years. Saturn circles the Sun at a distance of 1.43 x 1012 m. What is the orbital period of Saturn?

A small-sized 155-kg mass is located 1.50 m from a small-sized 275-kg mass, with both masses fixed in place. Where should you place a third small-sized mass so that the net gravitational force on it due to the original two masses is zero?

If the mass of the earth and all objects on it were suddenly doubled, but the size remained the same, the acceleration due to gravity at the surface would become

A certain planet has an escape speed V. If another planet has twice size and twice the mass of the first planet, its escape speed will be

The reason an astronaut in an earth satellite feels weightless is that

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 106 m, G = 6.67 × 10-11 N ∙ m2/kg2.)

Planet Z-34 has a mass equal to 1/3 that of Earth, a radius equal to 1/3 that of Earth, and an axial spin rate 1/2 that of Earth. With g representing, as usual, the acceleration due to gravity on the surface of Earth, the acceleration due to gravity on the surface of Z-34 is

What is the ratio of the escape speed of a rocket launched from sea level to the escape speed of one launched from Mt. Everest (an altitude of 8.85 km) ? The radius of the earth is 6.38 × 106 m.

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.9200g? The radius of the earth is 6.38 × 106 m.

An astronaut is in equilibrium when he is positioned 140 km from the center of asteroid X and 581 km from the center of asteroid Y, along the straight line joining the centers of the asteroids. What is the ratio of the masses X/Y of the asteroids?

A planet has two small satellites in circular orbits around the planet. The first satellite has a period 12.0 hours and an orbital radius 6.00 × 107 m. The second planet has a period 16.0 hours. What is the orbital radius of the second satellite?

Ekapluto is an unknown planet that has two moons in circular orbits. The table summarizes the hypothetical data about the moons. (G = 6.67 × 10^-11 N ∙ m²/kg²) The mass of Ekapluto is closest to

Neptune circles the Sun at a distance of 4.50 × 10¹² m once every 164 years. Saturn circles the Sun at a distance of 1.43 x 10¹² m. What is the orbital period of Saturn?

By how many newtons does the weight of a 100-kg person change when he goes from sea level to an altitude of 5.0 km if we neglect the earth's rotational effects? (The mean radius of the Earth is 6.38 × 10⁶ m, G = 6.67 × 10^-11 N ∙ m²/kg².)

What is the ratio of the escape speed of a rocket launched from sea level to the escape speed of one launched from Mt. Everest (an altitude of 8.85 km) ? The radius of the earth is 6.38 × 10⁶ m.

From what height above the surface of the earth should an object be dropped to initially experience an acceleration of 0.9200g? The radius of the earth is 6.38 × 10⁶ m.

A planet has two small satellites in circular orbits around the planet. The first satellite has a period 12.0 hours and an orbital radius 6.00 × 10⁷ m. The second planet has a period 16.0 hours. What is the orbital radius of the second satellite?