Physics CH 3

A boy throws a rock with an initial velocity of 1.17m/s at 30.0∘ above the horizontal. How long does it take for the rock to reach the maximum height of its trajectory?

5.97×10^−2 s

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are V0x = 660 m/s and V0y = 40 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the y-component of the acceleration of the shell at point P is closest to:

-10 m/s^2

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are V0x = 940 m/s and V0y = 96 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the y-coordinate of point P is closest to:

470 m

You are taking a turn at 31m/s on a ramp of radius 16m. What is your acceleration?

60.1 m/s^2

A rescue plane spots a survivor 192m directly below and releases an emergency kit with a parachute. If the package descends at a constant vertical acceleration of 7.15m/s2and the initial plane horizontal speed was 87.9m/s, how far away from the survivor will it hit the waves?

644 m

A wind farm generator uses a two-bladed propeller mounted on a pylon at a height of 20 m. The length of each propeller blade is 12 m. A tip of the propeller breaks off when the propeller is vertical. The fragment flies off horizontally, falls, and strikes the ground at P. Just before the fragment broke off, the propellor was turning uniformly, taking 1.2 s for each rotation. In the figure, the angle with respect to the vertical at which the fragment strikes the ground is closest to:

68°

An aircraft performs a maneuver called an aileron roll. During this maneuver, the plane turns like a screw as it maintains a straight flight path, by using its ailerons to set the wings in circular motion. Due to structural strength, the airplane can only withstand an acceleration of 3.4m/s2on its wing tips. If the wing span is 8.7m, what is the shortest time it can make a full turn when it performs an aileron roll?

7.1 s

A projectile is fired at time t = 0.0 s, from point 0 at the edge of a cliff, with initial velocity components of vox = 50 m/s and voy = 700 m/s. The projectile rises, then falls into the sea at point P. The time of flight of the projectile is 175 s. In the figure, the x-coordinate of the projectile when its y-component of velocity equals 560 m/s upward is closest to:

710 m

A projectile is fired at time t = 0.0 s, from point 0 at the edge of a cliff, with initial velocity components of vox = 60 m/s and voy = 700 m/s. The projectile rises, then falls into the sea at point P. The time of flight of the projectile is 175 s. In the figure, the x-coordinate of the projectile when its y-component of velocity equals 560 m/s upward is closest to:

860 m

Shown here are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object's velocity changing while its speed is not changing?

a going up, v going straight to the right

Shown here are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object slowing down and turning to its right?

a slanted to the left, v straight down

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are V0x = 250 m/s and V0y = 44 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the y-component of the velocity of the shell of point P is closest to:

0

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are V0x = 850 m/s and V0y = 73 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the y-component of the velocity of the shell of point P is closest to:

0

An aircraft performs a maneuver called an aileron roll. During this maneuver, the plane turns like a screw as it maintains a straight flight path, by using its ailerons to set the wings in circular motion. If it takes the plane 27s to complete the circle and each wing length is 4.7m, what is the acceleration of the wing tip?

0.25 m/s^2

A cat leaps to catch a bird. If the cat's jump was at 60.0° off the ground and its initial velocity was 3m/s, what is the highest point of its trajectory?

0.34 m

Two particles, A and B, are in uniform circular motion about a common center. The acceleration of particle A is 8.5 times that of particle B. Particle B takes 2.2 times as long for a rotation as particle A. The ratio of the radius of the motion of particle A to that of particle B is closest to:

1.8

A projectile is fired at time t = 0.0 s, from point 0 at the edge of a cliff, with initial velocity components of vox = 90 m/s and voy = 200 m/s. The projectile rises, then falls into the sea at point P. The time of flight of the projectile is 50 s. In the figure, the magnitude of the velocity at time t = 15.0 s is closest to:

104 m/s

A fisherman casts his bait toward the river at an angle of 25°. As the line unravels, he notices that the bait and hook reach a maximum height of 1.1m. What was the initial velocity he launched the bait with? Assume that the line exerts no appreciable drag force on the bait and hook.

11 m/s

A projectile is fired from the origin (at y = 0 m) as shown in the figure. The initial velocity components are V0x = 140 m/s and V0y = 84 m/s. The projectile reaches maximum height at point P, then it falls and strikes the ground at point Q. In the figure, the x-component of the velocity of the shell at point P is closest to:

140 m/s

A wind farm generator uses a two-bladed propeller mounted on a pylon at a height of 20 m. The length of each propeller blade is 12 m. A tip of the propeller breaks off when the propeller is vertical. The fragment flies off horizontally, falls, and strikes the ground at P. Just before the fragment broke off, the propellor was turning uniformly, taking 1.2 s for each rotation. In the figure, the distance from the base of the pylon to the point where the fragment strikes the ground is closest to:

160 m

A football kicker is attempting a field goal from 41m out. The ball is kicked and just clears the lower bar with a time of flight of 3.3s. If the angle of the kick was 45°, what was the initial speed of the ball?

17.6 m/s

A child is sitting on the outer edge of a merry-go-round that is 18 m in diameter. If the merry-go-round makes 2.8 rev/min, what is the velocity of the child in m/s?

2.6 m/s

You throw a rock horizontally off a cliff with a speed of 20 m/s. After two seconds, the magnitude of the velocity of the rock is closest to

28 m/s

A projectile is fired at time t = 0.0 s, from point 0 at the edge of a cliff, with initial velocity components of vox = 80 m/s and voy = 800 m/s. The projectile rises, then falls into the sea at point P. The time of flight of the projectile is 200 s. In the figure, the height H of the cliff is closest to:

36000 m

A projectile is fired at time t = 0.0 s, from point 0 at the edge of a cliff, with initial velocity components of vox = 30 m/s and voy = 500 m/s. The projectile rises, then falls into the sea at point P. The time of flight of the projectile is 125 s. In the figure, the horizontal distance D is closest to:

3750 m

Which of the following ideas is true about projectile motion with no air drag?

The horizontal motion is independent of the vertical motion.

Two bullets are fired simultaneously parallel to a horizontal plane. The bullets have different masses and different initial velocities. Which one will strike the plane first?

They strike the plane at the same time.