$$\frac{60 \times 1.61 \times 1000}{3600} \approx 27\ \mathrm{m/s}$$

Question 1

A car travels 120 meters east in 6 seconds. What is the car's average velocity?

Accepted Answer

$$v = \frac{120\ \mathrm{m}}{6\ \mathrm{s}} = 20\ \mathrm{m/s}$$\ to\ the\ east$

Question 2

Which of the following statements best describes the difference between speed and velocity?

Accepted Answer

Velocity contains information about the direction of motion while speed does not.

Question 3

A runner jogs 100 meters north, then 100 meters east. What is the magnitude of the runner's net displacement?

Accepted Answer

$$\sqrt{100^2$ + 100^2$} = 141\ \mathrm{m}$$

Question 4

If Sam walks 100 meters to the right, then 200 meters to the left, what is the direction of his net displacement vector?

Accepted Answer

Points to the left.

Question 5

Which of the following is a vector quantity?

Accepted Answer

Displacement

Question 6

A cyclist starts 3 miles east of a water tower and ends 2 miles west of the tower. What is the cyclist's displacement?

Accepted Answer

$$\Delta x = x_f - x_i = (-2\ \mathrm{mi}) - (3\ \mathrm{mi}) = -5\ \mathrm{mi}$$

Question 7

Which of the following is the correct SI unit for mass?

Accepted Answer

Kilogram (kg)

Question 8

A ball is thrown at an angle of $$60^\circ$$ above the horizontal. Which statement about the velocity vectors during its flight is correct?

Accepted Answer

The velocity vectors change both in magnitude and direction during the flight.

Question 9

A measurement is recorded as $$2.67 	imes 10^3$. How many significant figures does this value have?

Accepted Answer

3

Question 10

Which of the following best describes the particle model in physics?

Accepted Answer

It treats a moving object as if all its mass were concentrated at a single point.

Question 11

A goose flies 21 miles north, then 28 miles east. What is the straight-line distance from its starting point to its final position?

Accepted Answer

$$\sqrt{21^2$ + 28^2$} = 35\ \mathrm{mi}$$

Question 12

Which of the following is an example of a scalar quantity?

Accepted Answer

Speed

Question 13

A student walks 30 meters east, then 40 meters north. What is the magnitude of the displacement?

Accepted Answer

$$\sqrt{30^2$ + 40^2$} = 50\ \mathrm{m}$$

Question 14

Which of the following is the correct way to add two vectors $$\vec{A}$$ and $$\vec{B}$$ graphically?

Accepted Answer

Place the tail of $$\vec{B} at $$the tip of $$\vec{A}$$, then draw the resultant from the tail of $$\vec{A} to $$the tip of $$\vec{B}.$$

Question 15

A measurement is recorded as 0.430. How many significant figures does this value have?

Accepted Answer

3

Question 16

Which of the following is an order-of-magnitude estimate for the speed of walking in meters per second?

Accepted Answer

1 m/s

Question 17

A car moves at a constant speed of 60 miles per hour. What is this speed in meters per second? (Use $$1\ \mathrm{mi} \approx 1.61\ \mathrm{km})$$

Accepted Answer

$$\frac{60 	imes 1.61 	imes 1000}{3600} \approx 27\ \mathrm{m/s}$$

Question 18

Which of the following is the correct formula for average velocity?

Accepted Answer

$$v = \frac{\Delta x}{\Delta t}$$

Question 19

A triangle has sides of 6 cm and 8 cm. What is the length of the hypotenuse?

Accepted Answer

$$\sqrt{6^2$ + 8^2$} = 10\ \mathrm{cm}$$

Question 20

Which of the following is true about significant figures when multiplying measured values?

Accepted Answer

The answer should have the same number of significant figures as the value with the fewest significant figures.

Chapter 1: Representing Motion – Study Notes

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