Q: A car travels 120 km in 2 hours. What is its average speed, and how does this differ from its average velocity if the car returns to its starting point?

Average speed is $$60\ \text{km/h}$$; average velocity is $$0\ \text{km/h}$$ because displacement is zero.

Q: A vector $$ extbf{A}$$ has a magnitude of $$5$$ units and points $$53^ ext{o}$$ above the positive x-axis. What is its unit vector form?

$$\textbf{A} = 3\hat{i} + 4\hat{j}$$

Question 1

A car travels 120 km in 2 hours. What is its average speed, and how does this differ from its average velocity if the car returns to its starting point?

Accepted Answer

Average speed is $$60\ 	ext{km/h}$$; average velocity is $$0\ 	ext{km/h}$$ because displacement is zero.

Question 2

Which of the following best describes the difference between displacement and distance traveled?

Accepted Answer

Displacement is the straight-line change in position, while distance is the total length of the path traveled.

Question 3

A vector $$	extbf{A}$$ has a magnitude of $$5$$ units and points $$53^	ext{o}$$ above the positive x-axis. What is its unit vector form?

Accepted Answer

$$	extbf{A} = 3\hat{i} + 4\hat{j}$$

Question 4

A ball is thrown vertically upward with an initial velocity of $$10\ 	ext{m/s}. $$Using the kinematic equations, what is the maximum height reached? (Assume $$g = 9.8\ 	ext{m/s}^2)$$

Accepted Answer

$$5.1\ 	ext{m}$$

Question 5

Which of the following statements about significant figures is correct?

Accepted Answer

The number of significant figures in the result should reflect the least precise measurement used in the calculation.

Question 6

A projectile is launched at an angle of $$30^	ext{o}$$ with an initial speed of $$20\ 	ext{m/s}. $$What is the horizontal component of its velocity?

Accepted Answer

$$17.3\ 	ext{m/s}$$

Question 7

Which equation correctly expresses the relationship between angular speed $$\omega$$, period $$T$$, and frequency $$f in $$uniform circular motion?

Accepted Answer

$$\omega = \frac{2\pi}{T}$$

Question 8

A cyclist accelerates from rest at $$2\ 	ext{m/s}^2$$ for $$5$$ seconds. What is the final velocity?

Accepted Answer

$$10\ 	ext{m/s}$$

Question 9

In two-dimensional projectile motion, which statement is always true on planet Earth (neglecting air resistance)?

Accepted Answer

The horizontal acceleration is zero, and the vertical acceleration is $$-g.$$

Question 10

A particle moves in a circle of radius $$r at $$constant speed $$v. $$What is the magnitude of its centripetal acceleration?

Accepted Answer

$$a_c = \frac{v^2$}{r}$$

Question 11

A student converts $$5.0\ 	ext{m} to $$centimeters. Which answer is correct, considering significant figures?

Accepted Answer

$$500\ 	ext{cm}$$

Question 12

Which of the following best describes radial and tangential acceleration in circular motion?

Accepted Answer

Radial acceleration points toward the center; tangential acceleration is perpendicular to radial and changes speed.

Question 13

A vector $$	extbf{B} is $$given as $$	extbf{B} = 6\hat{i} - 8\hat{j}. $$What is its magnitude and direction (relative to the positive x-axis)?

Accepted Answer

Magnitude: $$10$$ units; Direction: $$-53^	ext{o}$$

Question 14

A rock is dropped from a cliff and hits the ground after $$3$$ seconds. What is its velocity just before impact? (Assume $$g = 9.8\ 	ext{m/s}^2)$$

Accepted Answer

$$29.4\ 	ext{m/s}$$ downward

Question 15

Which of the following is NOT a correct application of dimensional analysis?

Accepted Answer

Adding quantities with different units, such as meters and seconds.

Question 16

A projectile is launched horizontally from a $$45\ 	ext{m}$$ high cliff. How long does it take to hit the ground? (Assume $$g = 9.8\ 	ext{m/s}^2)$$

Accepted Answer

$$3.03\ 	ext{s}$$

Question 17

Which statement about coordinate systems is correct?

Accepted Answer

The choice of origin and positive directions affects only the sign of calculated quantities.

Question 18

A car moves with constant acceleration. Which kinematic equation would you use to find the displacement after time $$t$$?

Accepted Answer

$$x = x_0$ + v_0$ t + \frac{1}{2} a t^2$

Question 19

A runner moves $$100\ 	ext{m}$$ east, then $$50\ 	ext{m}$$ north. What is the magnitude of the displacement?

Accepted Answer

$$\sqrt{100^2$ + 50^2$} = 111.8\ 	ext{m}$$

Question 20

A satellite orbits Earth in uniform circular motion. Which statement is true about its acceleration?

Accepted Answer

Its acceleration is directed toward the center of the circle and has magnitude $$a_c = \frac{v^2$}{r}.$$

PHYS 180 Study Guide: Chapters 1–4 (Units, Kinematics, Vectors, and Circular Motion)

Study Guide - Practice Questions

Study Guide - Flashcards