Q: A car travels 53 mph. What is this speed in m/s? (1 mile = 1609 m, 1 hour = 3600 s)

$$53 \times \frac{1609}{3600} = 23.7 m/s$$

Q: A bus travels at 65 miles/hour for 30 minutes, stops for 15 minutes, then travels at 45 miles/hour for 3600 seconds. What is the total distance traveled by the bus in meters? (1 mile = 1609 m)

$$65 \times 0.5 \times 1609 + 45 \times 1 \times 1609 = 52,292 m$$

Q: A jack-o-lantern is dropped from a height of 12.5 m. How long does it take to hit the ground? (Assume $$g = 9.8 m/s$^2)$$

$$t = \sqrt{\frac{2h}{g}} = \sqrt{\frac{2 \times 12.5}{9.8}} = 1.6 s$$

Q: A vase is thrown vertically upwards with an initial velocity of 26.2 m/s. What is the maximum height it reaches above its initial position? (Assume $$g = 9.8 m/s$^2)$$

$$h = \frac{v^2$}{2g} = \frac{(26.2)^2$}{2 \times 9.8} = 35.0 m$$

Q: If George walks 1,170 m in 14 minutes, what is his resultant velocity in m/s?

$$\frac{1,170}{14 \times 60} = 1.39 m/s$$

Question 1

Which of the following quantities is a vector?

Accepted Answer

The displacement between your home and the school

Question 2

A car travels 53 mph. What is this speed in m/s? (1 mile = 1609 m, 1 hour = 3600 s)

Accepted Answer

$$53 	imes \frac{1609}{3600} = 23.7 m/s$$

Question 3

Which statement about vectors and scalars is TRUE?

Accepted Answer

The length of a vector represents the quantity's magnitude.

Question 4

A bus travels at 65 miles/hour for 30 minutes, stops for 15 minutes, then travels at 45 miles/hour for 3600 seconds. What is the total distance traveled by the bus in meters? (1 mile = 1609 m)

Accepted Answer

$$65 	imes 0.5 	imes 1609 + 45 	imes 1 	imes 1609 = 52,292 m$$

Question 5

A roller coaster car speeds up from 4 m/s to 22 m/s in 8 seconds. What is its average acceleration?

Accepted Answer

$$\frac{22 - 4}{8} = 2.25 m/s$^2$$

Question 6

A jack-o-lantern is dropped from a height of 12.5 m. How long does it take to hit the ground? (Assume $$g = 9.8 m/s$^2)$$

Accepted Answer

$$t = \sqrt{\frac{2h}{g}} = \sqrt{\frac{2 	imes 12.5}{9.8}} = 1.6 s$$

Question 7

A vase is thrown vertically upwards with an initial velocity of 26.2 m/s. What is the maximum height it reaches above its initial position? (Assume $$g = 9.8 m/s$^2)$$

Accepted Answer

$$h = \frac{v^2$}{2g} = \frac{(26.2)^2$}{2 	imes 9.8} = 35.0 m$$

Question 8

A bucket is kicked horizontally from a 20 m high cliff with a speed of 5 m/s. How far from the base of the cliff does the bucket land? (Assume $$g = 9.8 m/s$^2)$$

Accepted Answer

$$t = \sqrt{\frac{2h}{g}} = \sqrt{\frac{40}{9.8}} = 2.02 s$$; \ x = v t = 5 	imes 2.02 = 10.1$ m

Question 9

George walks 750 m East, then 900 m South. What is his resultant displacement?

Accepted Answer

$$\sqrt{750^2$ + 900^2$} = 1,170 m$$

Question 10

If George walks 1,170 m in 14 minutes, what is his resultant velocity in m/s?

Accepted Answer

$$\frac{1,170}{14 	imes 60} = 1.39 m/s$$

Question 11

A car travels in a straight line at a constant speed. What is its acceleration?

Accepted Answer

Zero, because the velocity does not change.

Question 12

Which of the following best describes a situation where distance is equal to displacement?

Accepted Answer

A car drives 100 m east in a straight line.

Question 13

On a velocity-time graph, what does the area under the curve represent?

Accepted Answer

The displacement of the object.

Question 14

A car's speedometer reads a constant 65 mph. Which of the following is TRUE?

Accepted Answer

The car's velocity may not be constant if its direction is changing.

Question 15

A baseball is thrown at 7.6 m/s. If the runner starts 0.18 s after the ball is thrown, how far has the ball traveled before the runner starts?

Accepted Answer

$$d = v t = 7.6 	imes 0.18 = 1.37 m$$

Question 16

A jack-o-lantern is dropped from rest from a height $$h. $$What is its velocity just before it hits the ground?

Accepted Answer

$$v = \sqrt{2gh}$$

Question 17

Which of the following is a correct statement about average velocity?

Accepted Answer

Average velocity is total displacement divided by total time.

Question 18

On a velocity-time graph, during which interval is the object at rest?

Accepted Answer

When the velocity is zero (horizontal line on the time axis).

Question 19

A student walks 6 m North, 12 m South, 4 m West, and 2 m East. What is the magnitude of the resultant displacement?

Accepted Answer

$$\sqrt{(12-6)^2$ + (4-2)^2$} = \sqrt{36 + 4} = 6.32 m$$

Kinematics and Vectors: Study Notes for Introductory Physics

Guida di studio - Domande di pratica

Study guide - Flashcard