Question 38

Question

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
102.5 m
b
40 m
c
250 m
d
0.025 m

Answer 1

To find the distance that David can travel, you can use the formula:

\[ \text{distance} = \text{speed} \times \text{time}. \]

Given that David's speed is 2.5 m/s and the time is 100 seconds, you can calculate the distance as follows:

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

So, the correct answer is:

c) 250 m.

Answer 2

Question 39
What is the difference between speed and velocity?

a
Velocity has time.
b
Velocity has distance.
c
Velocity has weight.
d
Velocity has direction.
Question 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
15 cm to the west
c
45 cm to the east
d
45 cm to the west

Answer 3

Question 39

The difference between speed and velocity is that:

d) Velocity has direction.

Speed is a scalar quantity, which means it only has magnitude (how fast something is going), while velocity is a vector quantity that has both magnitude and direction (how fast and in which direction something is moving).

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Question 40

To find the magnitude of the ant's displacement:

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

Displacement is calculated as the final position minus the original position. In this case:

• Total distance traveled east = +30 cm
• Total distance traveled west = -15 cm

Calculating the net displacement:

\[ \text{Displacement} = (30 , \text{cm east}) - (15 , \text{cm west}) = 30 , \text{cm} - 15 , \text{cm} = 15 , \text{cm east}. \]

So the correct answer is:

a) 15 cm to the east.