Question 1

A pilot drops a bomb from a plane flying horizontally at a constant speed. Neglecting air resistance, when the bomb hits the ground the horizontal location of the plane will

Accepted Answer

Since the plane is flying horizontally at a constant speed, it will continue to move forward at the same rate as the bomb falls straight down due to gravity. Therefore, the plane will be directly over the bomb when it hits the ground.

Question 2

A monkey is sitting at the top of a tree 20 m above ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the monkey remains seated at the top of the tree, how should the person aim the arrow containing the food so that the monkey gets the food?

Accepted Answer

The answer of A monkey is sitting at the top...

Question 3

FIGURE 3-1 
-Refer to Fig. 3-1. The components of vectors  and  are

Accepted Answer

The answer of FIGURE 3-1 
-Refer to Fig. 3-1. The...

Question 4

A monkey is sitting at the top of a tree 20 m above ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the person knows that the monkey is going to drop from the tree at the same instant that the person launches the food, how should the person aim the arrow containing the food?

Accepted Answer

The person should aim directly at the monkey because both the monkey and the arrow will be subject to the same gravitational acceleration, causing them to fall at the same rate.

Question 5

The eastward component of vector  is equal to the westward component of vector  and their northward components are equal. Which one of the following statements is correct for these two vectors?

Accepted Answer

The answer of The eastward component of vector  is...

Question 6

For general projectile motion, the horizontal component of a projectile's acceleration

Accepted Answer

The horizontal component of a projectile's velocity remains constant (assuming no air resistance or other external forces), and since acceleration is the rate of change of velocity, the horizontal component of acceleration must be zero.

Question 7

When a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed?

Accepted Answer

The answer of When a football in a field goal...

Question 8

Refer to Fig. 3-2. Vector  as expressed in terms of vectors  and  is given by

Accepted Answer

The answer of Refer to Fig. 3-2. Vector  as...

Question 9

A ball rolls off the edge of a table. The horizontal component of the ball's velocity remains constant during its entire trajectory because

Accepted Answer

The only force acting on the ball in the horizontal direction after it rolls off the table is its initial horizontal velocity. There are no other horizontal forces acting on it, so its initial velocity remains constant. The vertical velocity, on the other hand, is affected by gravity, which causes the ball to accelerate downwards.

Question 10

For a projectile launched horizontally, the vertical component of its velocity

Accepted Answer

The vertical component of velocity for a horizontally launched projectile increases continuously due to the acceleration caused by gravity.

Question 11

For general projectile motion, which statement is true when the projectile is at the highest point of its trajectory?

Accepted Answer

At the highest point of its trajectory, the vertical component of the projectile's velocity is zero, but the horizontal component remains constant. The acceleration due to gravity acts downward, making the velocity perpendicular to the acceleration at this point.

Question 12

The resultant vector  of two vectors  and  will have the minimum value when the angle between these vectors is which one of the following?

Accepted Answer

The answer of The resultant vector  of two vectors...

Question 13

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. Compare the time it takes each to reach the lake below.

Accepted Answer

The time it takes for an object to fall is only dependent on the height it falls from and not its initial velocity or its mass/weight. Therefore, both James and John will take the same amount of time to reach the surface of the lake.

Question 14

James and John dive from an overhang into the lake below. James simply drops straight down from the edge. John takes a running start and jumps with an initial horizontal velocity of 25 m/s. When they reach the lake below,

Accepted Answer

The answer of James and John dive from an overhang...

Question 15

For general projectile motion, the vertical component of a projectile's acceleration

Accepted Answer

The answer of For general projectile motion, the vertical component...

Question 16

For general projectile motion, the horizontal component of a projectile's velocity

Accepted Answer

The horizontal component of a projectile's velocity remains a non-zero constant throughout its motion. This is because there are no horizontal forces acting on the projectile (assuming negligible air resistance), so its velocity in the horizontal direction remains constant.

Question 17

An Olympic athlete throws a javelin at four different angles above the horizontal, each with the same speed: 30°, 40°, 60°, and 80°. Which two throws cause the javelin to land the same distance away?

Accepted Answer

The answer of An Olympic athlete throws a javelin at...

Question 18

A student kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory:

Accepted Answer

The answer of A student kicks a soccer ball in...

Question 19

FIGURE 3-2 
-Refer to Fig. 3-2. Vector  as expressed in terms of vectors  and  is given by

Accepted Answer

The answer of FIGURE 3-2 
-Refer to Fig. 3-2. Vector...

Question 20

For a projectile launched horizontally, the horizontal component of a projectile's velocity

Accepted Answer

The horizontal component of a projectile's velocity remains a non-zero constant because there is no force acting on the projectile in the horizontal direction to change its velocity. The projectile will continue to move at a constant speed horizontally unless acted upon by an external force.

Quiz 3: Kinematics in Two or Three Dimensions; Vectors