How would you solve these problems?

Question

Level 3

Q1

A plane travels at 425 km/h east for 300 km. What is the plane’s time?

1. 127,000 hours 
2. 1.4 hours
3. 0.7 hours
4. None of the above 

Q3

A balloon moves vertically upward at 5 m/s. This is an example of: 

1. Velocity
2. Speed
3. Acceleration
4. Displacement

Q2

A cheetah travels 65 mi/h north for 0.05 hours. What is the cheetah’s displacement?

1. 3.25 meters
2. 3.25 miles north
3. 1300 meters
4. 1300 miles north

Q4

A car travels 20 m/s east in 1.0 second. The displacement of the car at the end of this 1.0 second interval is:

1. 20 m
2. 20 m/s
3. 20 m/s east
4. 20 m east

Level 4

Q1

What is the magnitude of the object’s total displacement after 8 seconds?

1. 0 m
2. 2 m
3. 8 m
4. 16 m

Q2

What is the object’s velocity from 2-4 seconds?

1. 4 m/s
2. 2 m/s
3. 0 m/s
4. None of the above

Answer 1

Q1. A plane travels at 425 km/h east for 300 km.

Here we use the equation S = D / T where S = speed,; D = displacement (distance); T = time

Rearranging: T = D / S

= 300 / 425

= 12 / 17 hours

= 0.7 hours

Answer 3 is correct.

Q2. A cheetah travels 65 mi/h north for 0.05 hours. What is the cheetah’s displacement?

Rearranging the same formula: D = S x T

= 65 x 0.05

= 3.25 miles due north

Answer is 2 correct.

Q3. A balloon moves vertically upward at 5 m/s. This is an example of speed in a specific direction, whihc is is a velocity.

Answer 1 is correct.

Q4. A car travels 20 m/s east in 1.0 second. The displacement of the car at the end of this 1.0 second interval is: D = S x T

= 20 x 1.0

= 20 meters to the east

Answer 4 is correct.

Level 4, Q1. Form the graph, its displacement (on the Y-axis) is zero.

Answer 1 is correct.

Q2. S = D / T

Since the net displacement from 2 to 4 seconds is zero, S = 0 / 2 = 0 meters

Answer 3 is correct.

And we're done!