Question 1

A boy kicks a football from ground level with an initial velocity of 20 m/s at an angle of 30° above the horizontal. What is the horizontal distance to the point where the football hits the ground if we
Neglect air resistance?

Accepted Answer

The answer of A boy kicks a football from ground...

Question 2

A child throws a ball with an initial speed of 8.0 m/s at an angle of 40° above the
horizontal. The ball leaves her hand 1.0 m above the ground and experiences no
appreciable air resistance as it moves.
(a) How far from where the child is standing does the ball hit the ground?
(b) How long is the ball in flight before it hits the ground?
(c) What is the magnitude of the ball's velocity just before it hits the ground?

Accepted Answer

The answer of A child throws a ball with an...

Question 3

A projectile is fired from ground level at an angle above the horizontal on an airless planet where w  
The initial  x  and  y  components of its velocity are  86.6 m/s and  50.0m/s respectively. How long after firing does it take before the projectile hits the level ground?

Accepted Answer

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Question 4

An athlete participates in an interplanetary discus throw competition during an Olympiad that takes place on a planet where the acceleration due to gravity is  He throws the discus with
An initial velocity of 20 m/s at an angle of 6  ° from the vertical. Neglecting air resistance and the
Height of the discus at the point of release, what is the range of the discus?

Accepted Answer

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Question 5

A high-speed dart is shot from ground level with a speed of 150 m/s at an ang  ° above the horizontal. What is the vertical component of its velocity after 4.0 s if air resistance is neglected?

Accepted Answer

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Question 6

An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of  with the vertical. What is the length of the athlete's jump if air resistance is of no significance?

Accepted Answer

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Question 7

A projectile leaves the ground at 150 m/s and reaches a maximum height of 0.57 km. If
there was no air resistance, at what angle above the horizontal did it leave the ground?

Accepted Answer

The answer of A projectile leaves the ground at 150...

Question 8

A projectile is fired from ground level with an initial speed of 55.6 m/s at an angle o  above the horizontal. Neglect air resistance, take upward as the positive direction, and use  (a) Determine the time necessary for the projectile to reach its maximum height.
(b) Determine the maximum height reached by the projectile.
(c) Determine the horizontal and vertical components of the velocity vector at the
maximum height.
(d) Determine the horizontal and vertical components of the acceleration vector at the
maximum height.

Accepted Answer

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Question 9

A child is trying to throw a ball over a fence. She gives the ball an initial speed of 8.0 m/s at an angle of  ° above the horizontal. The ball leaves her hand 1.0 m above the ground and the fence is
2)0 m high. The ball just clears the fence while still traveling upwards and experiences no
Significant air resistance. How far is the child from the fence?

Accepted Answer

The answer of A child is trying to throw a...

Question 10

A child throws a ball with an initial speed of 8.0 m/s at an angle of  ° above the horizontal. The ball leaves her hand 1.0 m above the ground. At what angle below the horizontal does the ball
Approach the ground?

Accepted Answer

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Question 11

A boy throws a ball with an initial velocity of 25 m/s at an angle of  above the horizontal. If air resistance is negligible, how high above the projection point is the ball after 2.0 s?

Accepted Answer

The answer of A boy throws a ball with an...

Question 12

A wind farm generator uses a two-bladed propeller mounted on a pylon at a height of 20 m, as shown in the figure. The width of the pylon is very narrow, and the length of each propeller blade
Is 12 m. A tip of the propeller breaks off just when the propeller is vertical. The fragment flies off
Horizontally, falls, and strikes the ground at point P with negligible air resistance. Just before the
Fragment broke off, the propeller was turning uniformly, taking 1.2 s for each rotation. How far is
Point P from the base of the pylon?

Accepted Answer

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Question 13

A projectile is shot horizontally at 23.4 m/s from the roof of a building 55 m tall and
experiences negligible air resistance.
(a) Determine the time necessary for the projectile to reach the ground below.
(b) Determine the distance from the base of the building that the projectile lands.
(c) Determine the horizontal and vertical components of the velocity just before the
projectile reaches the ground.

Accepted Answer

The answer of A projectile is shot horizontally at 23.4...

Question 14

A person throws a ball horizontally from the top of a building that is 24.0 m above the ground level. The ball lands 100 m down range from the base of the building. What was the initial velocity
Of the ball? Neglect air resistance and use g = 9.81 m/s².

Accepted Answer

The time to fall 24.0 m is found using the equation $ t = \sqrt{\frac{2h}{g}} $. Substituting $ h = 24.0 $ m and $ g = 9.81 $ m/s² gives $ t \approx 2.21 $ s. The horizontal velocity is then $ v = \frac{d}{t} = \frac{100}{2.21} \approx 45.2 $ m/s.

Question 15

An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of  above the horizontal. How long does the athlete stay in the air, assuming no significant air resistance?

Accepted Answer

The answer of An athlete competing in the long jump...

Question 16

The horizontal and vertical components of the initial velocity of a football are 16 m/s and 20 m/s respectively. If there is no air resistance, how long does it take the football to reach the top of its
Trajectory?

Accepted Answer

The time to reach the top of its trajectory is found using the vertical component of the velocity and the acceleration due to gravity. The formula is $t = \frac{v}{g}$, where $v = 20 \, \text{m/s}$ (the vertical component of the initial velocity) and $g = 9.8 \, \text{m/s}^2$ (the acceleration due to gravity). Plugging in the values, $t = \frac{20}{9.8} \approx 2.0 \, \text{s}$, so the correct answer is D) 2.0 s.

Question 17

A rock is thrown from the roof of a building, with an initial velocity of 10 m/s at an angle
of 30° above the horizontal. The rock is observed to strike the ground 43 m from the base
of the building. What is the height of the building assuming no air resistance?

Accepted Answer

The answer of A rock is thrown from the roof...

Question 18

A projectile is fired at an angle above the horizontal at a location where  The initial x and y components of its velocity are 86.6 m/s and 50 m/s respectively. At what angle was the
Projectile fired above the horizontal?

Accepted Answer

The answer of A projectile is fired at an angle...

Question 19

At a location where g = 9.80 m/s², a projectile returns to its original height after 4.08
seconds, during which time it travels 76.2 meters horizontally. If air resistance can be
neglected, what was the projectile's initial speed?

Accepted Answer

The answer of At a location where g = 9.80...

Question 20

A projectile is fired from ground level with a speed of 150 m/s at an ang  above the horizontal on an airless planet where g = 10.0 m/s². What is the horizontal component of its velocity after 4.0
S?

Accepted Answer

The answer of A projectile is fired from ground level...

Quiz 3: Kinematics in Two Dimensions; Vectors

A boy kicks a football from ground level with an initial velocity of 20 m/s at an angle of 30° above the horizontal. What is the horizontal distance to the point where the football hits the ground if we Neglect air resistance?

A projectile is fired from ground level at an angle above the horizontal on an airless planet where w The initial x and y components of its velocity are 86.6 m/s and 50.0m/s respectively. How long after firing does it take before the projectile hits the level ground?

A high-speed dart is shot from ground level with a speed of 150 m/s at an ang ° above the horizontal. What is the vertical component of its velocity after 4.0 s if air resistance is neglected?

An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of with the vertical. What is the length of the athlete's jump if air resistance is of no significance?

A projectile leaves the ground at 150 m/s and reaches a maximum height of 0.57 km. If there was no air resistance, at what angle above the horizontal did it leave the ground?

A child throws a ball with an initial speed of 8.0 m/s at an angle of ° above the horizontal. The ball leaves her hand 1.0 m above the ground. At what angle below the horizontal does the ball Approach the ground?

A boy throws a ball with an initial velocity of 25 m/s at an angle of above the horizontal. If air resistance is negligible, how high above the projection point is the ball after 2.0 s?

A person throws a ball horizontally from the top of a building that is 24.0 m above the ground level. The ball lands 100 m down range from the base of the building. What was the initial velocity Of the ball? Neglect air resistance and use g = 9.81 m/s².

An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of above the horizontal. How long does the athlete stay in the air, assuming no significant air resistance?

The horizontal and vertical components of the initial velocity of a football are 16 m/s and 20 m/s respectively. If there is no air resistance, how long does it take the football to reach the top of its Trajectory?

A rock is thrown from the roof of a building, with an initial velocity of 10 m/s at an angle of 30° above the horizontal. The rock is observed to strike the ground 43 m from the base of the building. What is the height of the building assuming no air resistance?

A projectile is fired at an angle above the horizontal at a location where The initial x and y components of its velocity are 86.6 m/s and 50 m/s respectively. At what angle was the Projectile fired above the horizontal?

At a location where g = 9.80 m/s², a projectile returns to its original height after 4.08 seconds, during which time it travels 76.2 meters horizontally. If air resistance can be neglected, what was the projectile's initial speed?

A projectile is fired from ground level with a speed of 150 m/s at an ang above the horizontal on an airless planet where g = 10.0 m/s². What is the horizontal component of its velocity after 4.0 S?