The table below shows the mass and velocity of four objects. Which object has the least inertia?

Question

object mass(kg) velocity (m/s)
w 16 2
x 15 3
y 13 20
z 2 30

a
X
b
Z
c
Y
d
W

Answer 1

Inertia is a measure of an object's resistance to changes in its motion, and it is directly related to its mass. In this case, since we are only considering the mass of the objects (the velocity does not affect inertia), we can determine which object has the least inertia by comparing their masses.

Here are the masses of the objects:

• Object W: 16 kg
• Object X: 15 kg
• Object Y: 13 kg
• Object Z: 2 kg

Since object Z has the smallest mass (2 kg), it also has the least inertia.

Therefore, the answer is: b. Z

Answer 2

Shown in the diagram below is path A from point P1 to P2, along which a dog ran. Also shown is an arrow labeled B.

What do A and B represent in the diagram?

a
A represents the displacement the dog traveled, while B is a vector representing the change in position of the dog.
b
A represents the change in position the dog traveled, while B is a vector representing the distance of the dog.
c
A represents the distance the dog traveled, while B is a vector representing the displacement of the dog.
d
A represents the displacement the dog traveled, while B is a vector representing the distance of the dog.

Answer 3

In the context of physics, it's important to differentiate between distance and displacement:

• Distance is a scalar quantity that refers to how much ground an object has covered, regardless of its starting or ending point.
• Displacement is a vector quantity that refers to the change in position of an object from its starting point to its ending point, taking into account the direction.

Given the options and the context you provided, we can define:

• Path A would typically represent the actual distance the dog traveled.
• Arrow B would represent the displacement, showing the shortest path and direction from point P1 to point P2.

Based on this reasoning, the correct interpretation is:

c. A represents the distance the dog traveled, while B is a vector representing the displacement of the dog.

Answer 4

David is skateboarding at a speed of 2.5 m/s. How far can he travel on his skateboard in 100 seconds?

speed=distance / time

a
40 m
b
102.5 m
c
0.025 m
d
250 m

Answer 5

To calculate the distance David can travel on his skateboard, we can use the formula:

\[ \text{Distance} = \text{Speed} \times \text{Time} \]

Given:

• Speed = 2.5 m/s
• Time = 100 seconds

Now we can plug in the values:

\[ \text{Distance} = 2.5 , \text{m/s} \times 100 , \text{s} \] \[ \text{Distance} = 250 , \text{m} \]

So, the correct answer is: d. 250 m

Answer 6

What is the difference between speed and velocity?

a
Velocity has direction.
b
Velocity has weight.
c
Velocity has distance.
d
Velocity has time.

Answer 7

The correct answer is:

a. Velocity has direction.

To elaborate:

• Speed is a scalar quantity that describes how fast an object is moving, without regard to the direction of motion.
• Velocity is a vector quantity that includes both the speed of the object and the direction in which it is moving.

Thus, the key difference is that velocity incorporates direction, while speed does not.

Answer 8

An ant on a picnic table travels 30.0 cm to the east, then 15.0 cm to the west. What is the magnitude of the ant's displacement from its original position?

a
45 cm to the east
b
15 cm to the west
c
15 cm to the east
d
45 cm to the west

Answer 9

To find the magnitude of the ant's displacement from its original position, we need to consider both segments of its movement:

1. The ant travels 30.0 cm to the east.
2. Then it travels 15.0 cm to the west.

To calculate the net displacement:

• Starting from the original position, after moving 30.0 cm east, the ant is at +30.0 cm.
• When the ant then moves 15.0 cm to the west, it moves towards the west (which we can consider as a negative direction).

The net displacement (D) can be calculated as:

\[ D = 30.0 , \text{cm (east)} - 15.0 , \text{cm (west)} = 30.0 , \text{cm} - 15.0 , \text{cm} = 15.0 , \text{cm} \]

Since the remaining position (after moving 15 cm to the west) is still to the east, we have:

\[ D = 15.0 , \text{cm (east)} \]

Thus, the magnitude of the ant's displacement from its original position is:

c. 15 cm to the east.

Answer 10

A box is initially at rest on a frictionless surface. It then experiences two forces, as shown in the picture.

20 n from the left side of the box and 18 n on the right side of the box

Which best describes what will happen to the box?
a
It will move at an increasing speed to the left.
b
It will move at an increasing speed to the right.
c
It will move at a constant speed to the right.
d
It will move at a constant speed to the left.

Answer 11

To determine what will happen to the box under the influence of the two forces, we need to calculate the net force acting on it.

Given:

• A force of 20 N acting to the left (let's consider this as negative).
• A force of 18 N acting to the right (let's consider this as positive).

To find the net force (F_net), we can use the following calculation:

\[ F_{\text{net}} = F_{\text{right}} - F_{\text{left}} = 18 , \text{N} - 20 , \text{N} = -2 , \text{N} \]

The negative sign indicates that the net force is directed to the left.

Since the box experiences a net force to the left, it will start to accelerate to the left.

Based on this analysis, the best description of what will happen to the box is:

a. It will move at an increasing speed to the left.