Q: A ball is thrown horizontally from the top of a $$45\ \mathrm{m}$$ high cliff with an initial speed of $$10\ \mathrm{m/s}. $$How far from the base of the cliff does the ball land? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

$$10\sqrt{\dfrac{2 \times 45}{9.8}}\ \mathrm{m} \approx 30.3\ \mathrm{m}$$

Q: A $$0.5\ \mathrm{kg}$$ mass is attached to a string and swung in a horizontal circle of radius $$2\ \mathrm{m} at a $$speed of $$4\ \mathrm{m/s}. $$What is the tension in the string?

$$0.5 \times \dfrac{4^2$}{2} = 4\ \mathrm{N}$$

Q: A $$60\ \mathrm{kg}$$ person climbs a $$5\ \mathrm{m}$$ high ladder in $$10\ \mathrm{s}. $$What is the average power output against gravity? (Use $$g = 9.8\ \mathrm{m/s^2$})$$

$$\dfrac{60 \times 9.8 \times 5}{10} = 294\ \mathrm{W}$$

Q: A spring with a spring constant $$k = 200\ \mathrm{N/m} is $$compressed by $$0.1\ \mathrm{m}. $$What is the elastic potential energy stored in the spring?

$$\dfrac{1}{2} \times 200 \times (0.1)^2$ = 1\ \mathrm{J}$$

Q: A patient receives an X-ray with a wavelength of $$1 \times 10$$^{-10}$$\ \mathrm{m}. $$What is the energy of one photon of this X-ray? (Use $$h = 6.63 \times 10$$^{-34}$$\ \mathrm{J \cdot s}$$, $$c = 3.0 \times 10^8$\ \mathrm{m/s})$$

$$1.99 \times 10$$^{-15}$$\ \mathrm{J}$$

Q: A $$0.5\ \mathrm{kg}$$ block floats in water. What is the buoyant force acting on it?

$$0.5 \times 9.8 = 4.9\ \mathrm{N}$$

Q: A $$0.1\ \mathrm{kg}$$ mass oscillates on a spring with a period of $$0.5\ \mathrm{s}. $$What is the spring constant $$k$$?

$$k = \dfrac{4\pi^2$ \times 0.1}{(0.5)^2$} \approx 15.8\ \mathrm{N/m}$$

Question 1

A car accelerates uniformly from rest to a velocity of $$20\ \mathrm{m/s} in$$ $$5\ \mathrm{s}. $$What is the magnitude of its acceleration?

Accepted Answer

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

Question 2

A ball is thrown horizontally from the top of a $$45\ \mathrm{m}$$ high cliff with an initial speed of $$10\ \mathrm{m/s}. $$How far from the base of the cliff does the ball land? (Assume $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$10\sqrt{\dfrac{2 	imes 45}{9.8}}\ \mathrm{m} \approx 30.3\ \mathrm{m}$$

Question 3

A $$2\ \mathrm{kg}$$ object is acted upon by a net force of $$8\ \mathrm{N}. $$According to Newton's second law, what is the acceleration of the object?

Accepted Answer

$$4\ \mathrm{m/s^2$}$$

Question 4

A $$0.5\ \mathrm{kg}$$ mass is attached to a string and swung in a horizontal circle of radius $$2\ \mathrm{m} at a $$speed of $$4\ \mathrm{m/s}. $$What is the tension in the string?

Accepted Answer

$$0.5 	imes \dfrac{4^2$}{2} = 4\ \mathrm{N}$$

Question 5

A $$60\ \mathrm{kg}$$ person climbs a $$5\ \mathrm{m}$$ high ladder in $$10\ \mathrm{s}. $$What is the average power output against gravity? (Use $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$\dfrac{60 	imes 9.8 	imes 5}{10} = 294\ \mathrm{W}$$

Question 6

A spring with a spring constant $$k = 200\ \mathrm{N/m} is $$compressed by $$0.1\ \mathrm{m}. $$What is the elastic potential energy stored in the spring?

Accepted Answer

$$\dfrac{1}{2} 	imes 200 	imes (0.1)^2$ = 1\ \mathrm{J}$$

Question 7

A sound wave travels through air at $$340\ \mathrm{m/s}$$ with a frequency of $$1700\ \mathrm{Hz}. $$What is its wavelength?

Accepted Answer

$$0.2\ \mathrm{m}$$

Question 8

A patient receives an X-ray with a wavelength of $$1 	imes 10$$^{-10}$$\ \mathrm{m}. $$What is the energy of one photon of this X-ray? (Use $$h = 6.63 	imes 10$$^{-34}$$\ \mathrm{J \cdot s}$$, $$c = 3.0 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$1.99 	imes 10$$^{-15}$$\ \mathrm{J}$$

Question 9

A $$0.2\ \mathrm{m^3$}$$ sample of an ideal gas at $$300\ \mathrm{K}$$ and $$100\ \mathrm{kPa} is $$compressed isothermally to $$0.1\ \mathrm{m^3$}. $$What is the final pressure?

Accepted Answer

$$200\ \mathrm{kPa}$$

Question 10

A wire of length $$2\ \mathrm{m}$$ and resistance $$5\ \Omega is $$connected to a $$10\ \mathrm{V}$$ battery. What is the current through the wire?

Accepted Answer

$$2\ \mathrm{A}$$

Question 11

A $$1\ \mathrm{\mu C}$$ point charge is placed $$0.2\ \mathrm{m}$$ from another $$-2\ \mathrm{\mu C}$$ point charge. What is the magnitude of the electric force between them? (Use $$k = 9 	imes 10^9$\ \mathrm{N \cdot m^2$/C^2$$}$)

Accepted Answer

$$0.45\ \mathrm{N}$$

Question 12

A coil with $$100$$ turns and area $$0.01\ \mathrm{m^2$} is $$placed in a magnetic field of $$0.5\ \mathrm{T}. If $$the field is reduced to zero in $$0.1\ \mathrm{s}$$, what is the average induced emf?

Accepted Answer

$$5\ \mathrm{V}$$

Question 13

A radioactive isotope has a half-life of $$3$$ days. What fraction of the original sample remains after $$9$$ days?

Accepted Answer

$$\dfrac{1}{8}$$

Question 14

Which of the following best describes the function of the cell membrane in a biological cell?

Accepted Answer

It regulates the movement of substances into and out of the cell.

Question 15

A lens forms a real image $$30\ \mathrm{cm}$$ from the lens when the object is placed $$60\ \mathrm{cm}$$ from the lens. What is the focal length of the lens?

Accepted Answer

$$20\ \mathrm{cm}$$

Question 16

A $$0.5\ \mathrm{kg}$$ block floats in water. What is the buoyant force acting on it?

Accepted Answer

$$0.5 	imes 9.8 = 4.9\ \mathrm{N}$$

Question 17

Which of the following statements about the Bohr model of the atom is correct?

Accepted Answer

Electrons occupy fixed orbits with quantized energies.

Question 18

A patient’s body temperature rises from $$37^\circ \mathrm{C} to$$ $$39^\circ \mathrm{C}. $$What is the change in temperature in Kelvin?

Accepted Answer

$$2\ \mathrm{K}$$

Question 19

A $$0.1\ \mathrm{kg}$$ mass oscillates on a spring with a period of $$0.5\ \mathrm{s}. $$What is the spring constant $$k$$?

Accepted Answer

$$k = \dfrac{4\pi^2$ 	imes 0.1}{(0.5)^2$} \approx 15.8\ \mathrm{N/m}$$

Question 20

Which of the following best explains why metals are good conductors of electricity?

Accepted Answer

They have free electrons that can move easily through the lattice.

Biophysics Study Guide: Physics with Algebra Topics

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