$$F = 1,500 \times 2.78 = 4,170 N$$

Question 1

Which of the following quantities is a vector?

Accepted Answer

Velocity

Question 2

A car travels 60 km north and then 80 km east. What is the magnitude of its displacement?

Accepted Answer

$$\sqrt{60^2$ + 80^2$} = 100 km$$

Question 3

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

Accepted Answer

Speed is a scalar describing distance over time, velocity is a vector describing displacement over time.

Question 4

A runner completes a 400 m lap around a track in 50 seconds, ending at the starting point. What is the runner's average velocity?

Accepted Answer

$$0 m/s$$

Question 5

A car accelerates from rest to $$30 km/h in$$ $$5$$ seconds. What is its acceleration in $$\mathrm{m\ s$$^{-2}$$}$$? (1 km/h = 0.2778 m/s)

Accepted Answer

$$a = \frac{8.33\ \mathrm{m/s}}{5\ \mathrm{s}} = 1.67\ \mathrm{m\ s$$^{-2}$$}$$

Question 6

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

Accepted Answer

Distance

Question 7

A cyclist travels 10 km east, then 10 km west in 1 hour. What is the cyclist's average speed and average velocity?

Accepted Answer

Average speed: $$20 km/h$$, Average velocity: $$0 km/h$$

Question 8

Which of Newton's laws explains why passengers lurch forward in a car when it suddenly stops?

Accepted Answer

Newton's first law

Question 9

A 1,500 kg car accelerates from $$0 to$$ $$27.8 m/s in$$ $$10$$ seconds. What is the net force applied to the car?

Accepted Answer

$$F = 1,500 	imes 2.78 = 4,170 N$$

Question 10

Which equation correctly expresses Newton's second law of motion?

Accepted Answer

$$F = m a$$

Question 11

A swimmer pushes water backwards with her feet and moves forward. Which law explains this motion?

Accepted Answer

Newton's third law

Question 12

If a force of $$10 N is $$applied to a $$2 kg $$object, what is its acceleration?

Accepted Answer

$$a = \frac{10}{2} = 5\ \mathrm{m\ s$$^{-2}$$}$$

Question 13

Which of the following statements about vectors is TRUE?

Accepted Answer

Vectors have both magnitude and direction.

Question 14

A ball is thrown straight up with an initial velocity of $$10 m/s. $$What is its velocity at the top of its path?

Accepted Answer

$$0 m/s$$

Question 15

Which of the following is NOT a vector quantity?

Accepted Answer

Distance

Question 16

A force of $$50 N is $$applied to a box, causing it to accelerate at $$2 m/s$^2. $$What is the mass of the box?

Accepted Answer

$$m = \frac{50}{2} = 25 kg$$

Question 17

Which of the following best illustrates Newton's third law?

Accepted Answer

A rocket launching as exhaust gases are expelled downward

Question 18

If the net force on an object is zero, what can be said about its motion?

Accepted Answer

It must be moving at constant velocity or at rest.

Question 19

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

Accepted Answer

kg m/s$$^2$$

Question 20

A person walks 3 km north, then 4 km east. What is the total distance and displacement?

Accepted Answer

Distance: 7 km, Displacement: 5 km

Foundations of Physics: Scalars, Vectors, Velocity, Acceleration, and Newton's Laws

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