Question 1

A football is kicked with a speed of 18 m/s at an angle of 65° to the horizontal.
-How far does the football travel horizontally before it hits the ground?

Accepted Answer

A) 18 m 
B) 25 m 
C) 36 m 
D) 48 m 
E) 72 m

Question 2

3-10
During football practice, a football is kicked with a speed of 22 m/s at an angle of 60.0° relative to the positive x direction.At that instant, an observer rides past the football in a car that moves with a constant speed of 11 m/s in the positive x direction.
-Determine the initial velocity of the ball relative to the observer in the car.

Accepted Answer

A) 19 m/s in the +y direction 
B) 11 m/s in the +y direction 
C) 19 m/s at 60° to the +x direction 
D) 33 m/s at 60° to the +x direction 
E) 17 m/s at 60° to the +x direction

Question 3

A basketball player is running at a constant speed of 2.5 m/s when he tosses a basketball upward with a speed of 6.0 m/s.How far does the player run before he catches the ball? Ignore air resistance.

Accepted Answer

A) 3.1 m 
B) 4.5 m 
C) The ball cannot be caught because it will fall behind the player. 
D) 6.0 m 
E) 7.5 m

Question 4

3-5
A shell is fired with a horizontal velocity in the positive x direction from the top of an 80-m high cliff.The shell strikes the ground 1330 m from the base of the cliff.The drawing is not to scale. 
-An arrow is shot horizontally from a height of 4.9 m above the ground.The initial speed of the arrow is 45 m/s.Neglecting friction, how long will it take the arrow to hit the ground?

Accepted Answer

A) 9.2 s 
B) 6.0 s 
C) 1.0 s 
D) 1.4 s 
E) 4.6 s

Question 5

A GPS tracking device is placed in a police dog to monitor its whereabouts relative to the police station.At time t1 = 23 min, the dog's displacement from the station is 1.2 km, 33° north of east.At time t2 = 57 min, the dog's displacement from the station is 2.0 km, 75° north of east.Find the magnitude and direction of the dog's average velocity between these two times.

Accepted Answer

A) 0.52 m/s, 88° north of east 
B) 1.4 m/s, 31° west of north 
C) 1.6 m/s, 42° north of east 
D) 0.67 m/s, 21° west of north 
E) 0.80 m/s, 42° west of north

Question 6

Which statement is true concerning the ball when it is at C, the highest point in its trajectory?

Accepted Answer

A) The ball's velocity and acceleration are both zero. 
B) The ball's velocity is perpendicular to its acceleration. 
C) The ball's velocity is not zero, but its acceleration is zero. 
D) The ball's velocity is zero, but its acceleration is not zero. 
E) The horizontal and vertical components of the ball's velocity are equal.

Question 7

An airplane traveling north at 400 m/s is accelerated due east at a rate of 50 m/s2 for 6 s.If the effects of air resistance and gravity are ignored, what is the final speed of the plane?

Accepted Answer

A) 300 m/s 
B) 400 m/s 
C) 500 m/s 
D) 700 m/s 
E) 800 m/s

Question 8

On a two lane highway, a car is following a pickup truck.At one instant, the car has a speed of 32 m/s and is 184 m behind the truck.At the same time, the truck has a speed of 28 m/s.If neither vehicle accelerates, how long will it take the car to catch up to the truck?

Accepted Answer

A) 4.8 s 
B) 24 s 
C) 46 s 
D) 82 s 
E) 96 s

Question 9

A projectile is fired horizontally with an initial speed of 50.0 m/s.Neglect air resistance.
-What is the speed of the projectile 3.00 s after it is fired?

Accepted Answer

A) 29.4 m/s 
B) 50.0 m/s 
C) 58.0 m/s 
D) 79.4 m/s 
E) 98.6 m/s

Question 10

3-4
A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively.
-Approximately how long does it take the projectile to reach the highest point in its trajectory?

Accepted Answer

A) 1 s 
B) 2 s 
C) 4 s 
D) 8 s 
E) 16 s

Question 11

A block is at rest on a rough inclined plane and is connected to an object with the same mass as shown.The rope may be considered massless; and the pulley may be considered frictionless.The coefficient of static friction between the block and the plane is µS1U1B1sS1U1B0; and the coefficient of kinetic friction is $\mu$S1U1B1kS1U1B0. 
-A park ranger wanted to measure the height of a tall tree.The ranger stood 9.50 m from the base of the tree; and he observed that his line of sight made an angle of 65.2° above the horizontal as he looked at the top of the tree.The park ranger's eyes are 1.80 m above the ground.What is the height of the tree?

Accepted Answer

A) 5.84 m 
B) 8.77 m 
C) 11.7 m 
D) 17.3 m 
E) 22.4 m

Question 12

A tennis ball is thrown upward at an angle from point A.It follows a parabolic trajectory and hits the ground at point D.At the instant shown, the ball is at point B.Point C represents the highest position of the ball above the ground. 
-While in flight, how do the x and y components of the velocity vector of the ball compare at the points B and C?

Accepted Answer

A) The velocity components are non-zero at B and zero at C. 
B) The x components are the same; the y component at C is zero m/s. 
C) The x components are the same; the y component has a larger magnitude at C than at B. 
D) The x component is larger at C than at B; the y component at B points up while at C, it points downward. 
E) The x component is larger at B than at C; the y component at B points down while at C, it points upward.

Question 13

3-3
A projectile is fired at an angle of 55.0° above the horizontal with an initial speed of 35.0 m/s.
-What is the magnitude of the horizontal component of the projectile's displacement at the end of 2 s?

Accepted Answer

A) 30 m 
B) 40 m 
C) 10 m 
D) 20 m 
E) 50 m

Question 14

A car travels due east at 22 m/s.It makes a turn due south and continues to travel at 22 m/s. What is the change in velocity of the car?

Accepted Answer

A) 22 m/s, due east 
B) 22 m/s, due south 
C) 31 m/s, 45° south of west 
D) 31 m/s, 45° south of east 
E) zero m/s

Question 15

A projectile is fired horizontally with an initial speed of 50.0 m/s.Neglect air resistance.
-What is the magnitude of the displacement of the projectile 3.00 s after it is fired?

Accepted Answer

A) 29.4 m 
B) 44.1 m 
C) 150 m 
D) 156 m 
E) 194 m

Question 16

3-11
Two cars approach each other on a straight and level road.Car A is traveling at 75 km/h, due north and car B is traveling at 45 km/h, due south.Both velocities are measured relative to the ground.
-At a certain instant, the distance between the cars is 15 km.How long will it take, in seconds, from that instant for the two cars to meet?

Accepted Answer

A) 450 s 
B) 900 s 
C) 720 s 
D) 1200 s 
E) 1900 s

Question 17

A bullet is aimed at a target on the wall a distance L away from the firing position.Because of gravity, the bullet strikes the wall a distance $\Delta$y below the mark as suggested in the figure. Note: The drawing is not to scale.  If the distance L was half as large and the bullet had the same initial velocity, how would $\Delta$y be affected?

Accepted Answer

A) ($\Delta$y will double.) 
B) ($\Delta$y will be half as large.) 
C) ($\Delta$y will be four times larger.) 
D) ($\Delta$y will be one fourth as large.) 
E) ($\Delta$y is not possible to determine unless numerical values are given for the distances.)

Question 18

3-4
A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively.
-What is the magnitude of the projectile's velocity just before it strikes the ground?

Accepted Answer

A) zero m/s 
B) 9.8 m/s 
C) 30 m/s 
D) 40 m/s 
E) 50 m/s

Question 19

At which point is the velocity vector changing most rapidly with time?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) It is changing at the same rate at all four points.

Question 20

A rock is kicked horizontally at a speed of 15 m/s from the edge of a cliff.The rock strikes the ground 65 m from the foot of the cliff of height H as suggested in the figure, which is not drawn to scale.Neglect air resistance. 
-How long is the rock in the air?

Accepted Answer

A) 1.0 s 
B) 1.2 s 
C) 4.0 s 
D) 5.5 s 
E) 11.2 s

Exam 3: Kinematics in Two Dimensions

A football is kicked with a speed of 18 m/s at an angle of 65° to the horizontal. -How far does the football travel horizontally before it hits the ground?

A basketball player is running at a constant speed of 2.5 m/s when he tosses a basketball upward with a speed of 6.0 m/s.How far does the player run before he catches the ball? Ignore air resistance.

Which statement is true concerning the ball when it is at C, the highest point in its trajectory?

An airplane traveling north at 400 m/s is accelerated due east at a rate of 50 m/s² for 6 s.If the effects of air resistance and gravity are ignored, what is the final speed of the plane?

On a two lane highway, a car is following a pickup truck.At one instant, the car has a speed of 32 m/s and is 184 m behind the truck.At the same time, the truck has a speed of 28 m/s.If neither vehicle accelerates, how long will it take the car to catch up to the truck?

A projectile is fired horizontally with an initial speed of 50.0 m/s.Neglect air resistance. -What is the speed of the projectile 3.00 s after it is fired?

3-4 A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. -Approximately how long does it take the projectile to reach the highest point in its trajectory?

3-3 A projectile is fired at an angle of 55.0° above the horizontal with an initial speed of 35.0 m/s. -What is the magnitude of the horizontal component of the projectile's displacement at the end of 2 s?

A car travels due east at 22 m/s.It makes a turn due south and continues to travel at 22 m/s. What is the change in velocity of the car?

A projectile is fired horizontally with an initial speed of 50.0 m/s.Neglect air resistance. -What is the magnitude of the displacement of the projectile 3.00 s after it is fired?

3-4 A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. -What is the magnitude of the projectile's velocity just before it strikes the ground?

At which point is the velocity vector changing most rapidly with time?

A rock is kicked horizontally at a speed of 15 m/s from the edge of a cliff.The rock strikes the ground 65 m from the foot of the cliff of height H as suggested in the figure, which is not drawn to scale.Neglect air resistance. -How long is the rock in the air?