Question 1

Which of the following statements best describes a physical law in physics?

Accepted Answer

A physical law is a brief description of how nature behaves in a broad set of circumstances.

Question 2

A laboratory measurement yields a mass of 0.00930 kg. How many significant figures does this value have?

Accepted Answer

3

Question 3

Which of the following is the correct SI base unit for electric current?

Accepted Answer

Ampere (A)

Question 4

Convert 25 millimeters (mm) to meters (m) using scientific notation.

Accepted Answer

$$2.5 	imes 10$$^{-3}$$ m

Question 5

Which of the following correctly expresses 0.0000800 A in scientific notation with the correct number of significant figures?

Accepted Answer

$$8.00 	imes 10$$^{-5}$$ A

Question 6

A car is traveling at a speed of 38.0 m/s. What is this speed in kilometers per hour (km/h)?

Accepted Answer

$$136.8 km/h$$

Question 7

Which of the following is NOT a correct rule for determining significant figures?

Accepted Answer

All zeros in a number without a decimal point are significant.

Question 8

The area $$A of a $$rectangle is given by $$A = l w$$, where $$l is $$length and $$w is $$width. What is the dimension of area?

Accepted Answer

$$[L^2$]$$

Question 9

Which of the following equations is dimensionally correct for velocity $$v in $$terms of acceleration $$a$$ and time $$t$$?

Accepted Answer

$$v = a t$$

Question 10

A physical quantity has the unit $$\mathrm{kg} \cdot \mathrm{m}^2 / \mathrm{s}^2. $$Which of the following quantities has this unit?

Accepted Answer

Kinetic energy

Question 11

A speed limit sign reads 55 miles per hour (mi/h). What is this speed in meters per second (m/s)? (1 mi = 1609 m)

Accepted Answer

$$24.6 m/s$$

Question 12

Which prefix corresponds to a multiplying factor of $$10^{-6}$$?

Accepted Answer

Micro-

Question 13

A rectangular room has a floor area of 880 ft$$^2. $$What is the area in square meters (m$$^2$$)? (1 ft = 0.3048 m)

Accepted Answer

$$81.8 m$^2$$

Question 14

Which of the following is a derived SI unit?

Accepted Answer

Newton (N)

Question 15

The gravitational constant $$G$$ appears in Newton's law of universal gravitation: $$F = G \frac{m_1$ m_2$}{r^2$}. $$What are the SI units of $$G$$?

Accepted Answer

$$\mathrm{m}^3 \cdot \mathrm{kg}^{-1} \cdot \mathrm{s}^{-2}$$

Question 16

Which of the following best describes the purpose of dimensional analysis in physics?

Accepted Answer

To check the correctness of equations and to find the units of physical quantities.

Question 17

A student adds $$4.75 m $$and $$0.4168 m. $$What is the correct result with the proper number of decimal places?

Accepted Answer

Question 18

Which of the following is the correct scientific notation for the number 1234.56 with the correct number of significant figures?

Accepted Answer

$$1.23456 	imes 10^3$

Question 19

A formula for the braking distance of a car is $$d = b v^2$, where d$ is distance in meters and v$ is velocity in m/s. What are the SI units of b$?

Accepted Answer

$$\mathrm{s}^2 / \mathrm{m}$$

Chapter 1: Measurements in Physics – Models, Units, and Analysis

Study Guide - Practice Questions