Question 1

An airplane that flies at 100 km/h in a 100 km/h hurricane crosswind has a ground speed of

Accepted Answer

A) 0 km/h. 
B) 100 km/h. 
C) 141 km/h. 
D) 200 km/h.

Question 2

Consider a moon that orbits one of our most distant planets in an elliptical path.The distance that the moon covers each day is

Accepted Answer

A) greatest when the moon is closest to the planet. 
B) greatest when the moon is furthest from the planet. 
C) the same regardless of its distance from the sun. 
D) the same regardless of its distance from the planet.

Question 3

Rockets that launch satellites into orbit need less thrust when fired from

Accepted Answer

A) Cape Canaveral. 
B) Edwards Air Force Base in California. 
C) Hawaii. 
D) Location does not bear on the required rocket thrust.

Question 4

The Early Bird communication satellite hovers over the same point on Earth's equator indefinitely.This is because

Accepted Answer

A) forces other than Earth's gravity act on it. 
B) it pulls as hard on the Earth as the earth pulls on it. 
C) it is beyond the main pull of Earth gravity. 
D) it is kept aloft by ground control. 
E) its orbital period is 24 hours.

Question 5

A projectile is fired horizontally in a region of no air resistance.The projectile maintains its horizontal component of velocity because

Accepted Answer

A) it is not acted on by any forces. 
B) it is not acted on by any horizontal forces. 
C) it has no vertical component of velocity to begin with. 
D) the net force acting on it is zero. 
E) none of these

Question 6

An object is thrown vertically into the air.Because of air resistance,the time for its descent will be

Accepted Answer

A) longer than the ascent time. 
B) shorter than the ascent time. 
C) equal to the ascent time. 
D) Not enough information given to say.

Question 7

A gun with a muzzle velocity of 100 m/s is fired horizontally from a tower.Neglecting air resistance,how far downrange will the bullet be 1 second later?

Accepted Answer

A) 50 m 
B) 98 
C) 100 
D) 490 
E) none of these

Question 8

What prevents satellites such as the space shuttle from falling?

Accepted Answer

A) gravity 
B) centripetal force 
C) centrifugal force 
D) the absence of air drag 
E) Nothing;they are continually falling as they orbit the Earth.

Question 9

Planets would crash into the sun if it weren't for

Accepted Answer

A) their tangential velocities. 
B) their vast distances from the sun. 
C) the inverse-square law. 
D) their relatively small masses. 
E) the fact that they are beyond the main gravitation of the sun.

Question 10

Which of the following is not a vector quantity?

Accepted Answer

A) velocity 
B) speed 
C) acceleration 
D) None are vector quantities. 
E) All are vector quantities.

Question 11

A projectile is fired into the air at an angle of 50 degrees with the ground and lands on a target that is at the same level at which the projectile started.It will also land on the target if it is fired at an angle of

Accepted Answer

A) 40 degrees. 
B) 45 degrees. 
C) 55 degrees. 
D) 60 degrees. 
E) none of these

Question 12

A stone is thrown horizontally from the top of a cliff.One second after it has left your hand,its vertical distance below the top of the cliff is

Accepted Answer

A) 5 m. 
B) 10 m. 
C) 15 m.

Question 13

From Earth,one satellite appears to overtake another.The faster satellite is

Accepted Answer

A) higher. 
B) lower. 
C) smaller. 
D) can't say

Question 14

The speeds of the planets about the sun depend on

Accepted Answer

A) their distances from the sun. 
B) the masses of the planets. 
C) their periods of rotation. 
D) None of the above are correct.

Exam 10: Projectile and Satellite Motion