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

Question

speed = distance/time

A) 0.025 m
B) 102.5 m
C) 250 m
D) 40 m

39. What is the difference between speed and velocity?

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

40. 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
15 cm to the east
b
45 cm to the west
c
45 cm to the east
d
15 cm to the west

41. Which statement is correct about the two objects?

a
Objects X and Y are traveling at the same speed.
b
Objects X and Y are speeding up over time.
c
Both are traveling at a constant speed, but Object X is traveling at a faster speed than Object Y.
d
Neither object is traveling at a constant speed, and Object X is traveling at a slower speed than Object Y.

Answer 1

Let's go through each question step by step.

Question 38: David's skateboard distance.

Given:

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

Using the formula: \[ \text{Distance} = \text{Speed} \times \text{Time} \] \[ \text{Distance} = 2.5 , \text{m/s} \times 100 , \text{s} = 250 , \text{m} \]

So, the answer is: C) 250 m

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Question 39: Difference between speed and velocity.

The primary difference between speed and velocity is that velocity includes direction, while speed does not.

So, the correct answer is: b) Velocity has direction.

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Question 40: Ant's displacement.

The ant's movements:

• Travels 30.0 cm east
• Travels 15.0 cm west

Net displacement can be calculated as: \[ \text{Displacement} = \text{Distance East} - \text{Distance West} \] \[ \text{Displacement} = 30.0 , \text{cm} - 15.0 , \text{cm} = 15.0 , \text{cm} , \text{to the east} \]

So, the answer is: a) 15 cm to the east

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Question 41: Statement about two objects.

Without specific data about the two objects, it's difficult to determine the correct choice. However, assessing the options generally:

• If both objects are traveling at constant speed, option a would be true.
• If both are accelerating, option b would be true.
• If one is moving faster than the other at constant speeds, option c would be true.
• If both are not at constant speed and one object is slower, then option d would be true.

Assuming no additional context, we can lean towards recognizing that speed comparison typically involves clearly defined parameters, which aren't present here. Hence, I cannot definitively select an option without additional context on "Objects X and Y."

If there was more context provided regarding their speeds or acceleration, I could help specify the correct answer further.