Physics introduction
What does physics study? A) Only motion B) Matter, energy, motion, forces, and their interactions C) Only living organisms D) Only chemicals
B
Which instrument would be most appropriate for measuring the mass of a small object? A) Stopwatch B) Thermometer C) Balance D) Ruler
C — Balance
Approximately how many centimeters are in 1 inch?
2.54 cm
Write 5,000 in scientific notation.
5 × 10³
Name three branches of physics.
Possible answers: mechanics, thermodynamics, optics, electromagnetism, acoustics, quantum physics, nuclear physics, etc.
Which situation is an example of physics in everyday life? A) A plant growing B) A ball falling from a table C) Memorizing a poem D) Learning a language
B
What is the most widely used measurement system in science?
The International System of Units (SI).
Convert 10 inches to centimeters. Use 1 in = 2.54 cm.
25.4 cm
Write 0.00032 in scientific notation.
3.2 × 10⁻⁴
Which branch of physics studies motion, forces, and the behavior of objects?
Mechanics.
“Physics only studies things we can see.” Is this statement correct? Explain.
No. Physics also studies phenomena we cannot directly see, such as electric fields, magnetic fields, atoms, and waves.
Which SI unit is used to measure length? A) kilogram B) meter C) second D) kelvin
kilogram B) meter C) second D) kelvin
B — meter (m)
A person is 5 feet 6 inches tall. Convert their height to centimeters. Use 1 ft = 12 in and 1 in = 2.54 cm.
5 ft = 60 in; + 6 = 66 in → 167.64 cm
Write 6.7 × 10⁸ in ordinary decimal notation.
670,000,000
Which branch of physics is most directly involved in studying light, lenses, mirrors, and cameras?
Optics.
Why is measurement important in physics instead of simply describing something as “very fast,” “very heavy,” or “very far”?
Measurements provide quantitative, objective, and comparable information that can be tested and communicated.
Why would it be a problem if every country used completely different units for scientific measurements?
It would make measurements difficult to compare, communicate, reproduce, and convert, increasing the possibility of errors.
A car is traveling at 60 miles per hour. Using 1 mile ≈ 1.609 km, approximately how fast is it traveling in km/h?
60 × 1.609 = 96.54 km/h
Which number is greater: 4.5 × 10⁶ or 8.2 × 10⁵? How do you know?
4.5 × 10⁶. Its exponent is larger, so its order of magnitude is greater.
A company is designing a smartphone camera. Name at least two branches of physics that could be involved and explain how.
Optics → lenses and light; electromagnetism/electronics → sensors, electrical signals, and circuits.
Why is saying “the table is 2 long” incomplete when describing its length?
Because a numerical value needs a unit. We should say 2 meters, 2 feet, 2 centimeters, etc.
A NASA engineer in the United States gives a spacecraft measurement in feet, while another team uses meters. Why could this create a serious problem?
If the measurements are interpreted incorrectly or not converted properly, the teams could use incorrect values, potentially causing major engineering or mission errors.
A package has a mass of 10 lb. Using 1 lb ≈ 0.4536 kg, what is its mass in kilograms? If a machine can carry a maximum of 4.5 kg, can it safely carry the package?
10 × 0.4536 = 4.536 kg. No, it slightly exceeds the 4.5 kg limit.
A scientist measures the diameter of a cell as 0.000008 m. Express this measurement in scientific notation.
8 × 10⁻⁶ m
Engineers are designing an electric car. Name at least three branches of physics that could be applied during its design and explain what each contributes.
Mechanics → motion, forces, braking, suspension; electromagnetism → electric motor and circuits; thermodynamics → heat, battery temperature, and energy efficiency. Other valid answers could include materials/solid-state or fluid dynamics depending on the design aspect.