Q: A 2 kg object moving at $$3\ \mathrm{m/s}$$ collides and sticks to a 1 kg object at rest. What is their final velocity after the collision?

$$v_f = \frac{(2\ \mathrm{kg} \times 3\ \mathrm{m/s}) + (1\ \mathrm{kg} \times 0)}{2\ \mathrm{kg} + 1\ \mathrm{kg}} = 2\ \mathrm{m/s}$$

Question 1

A car accelerates from rest to 20 m/s in 5 seconds. What is its average acceleration?

Accepted Answer

$$a = \frac{\Delta v}{\Delta t} = \frac{20\ \mathrm{m/s} - 0}{5\ \mathrm{s}} = 4\ \mathrm{m/s^2$}$$

Question 2

Which of the following best distinguishes a vector from a scalar?

Accepted Answer

A vector has both magnitude and direction, while a scalar has only magnitude.

Question 3

A ball is thrown straight up with an initial velocity of $$10\ \mathrm{m/s}. $$Ignoring air resistance, what is the velocity of the ball when it returns to its starting point?

Accepted Answer

$$-10\ \mathrm{m/s}$$

Question 4

Which of Newton's Laws explains why passengers lurch forward in a car that suddenly stops?

Accepted Answer

Newton's First Law (Law of Inertia)

Question 5

A 5 kg object is acted on by a net force of 20 N. What is its acceleration?

Accepted Answer

$$a = \frac{F}{m} = \frac{20\ \mathrm{N}}{5\ \mathrm{kg}} = 4\ \mathrm{m/s^2$}$$

Question 6

A box is pulled at constant velocity across a horizontal surface. Which statement is true about the forces acting on the box?

Accepted Answer

The net force on the box is zero.

Question 7

Which of the following is an example of work being done?

Accepted Answer

A person lifts a box vertically upward.

Question 8

A satellite orbits Earth in a circular path. Which force provides the centripetal acceleration?

Accepted Answer

Gravitational force

Question 9

Which of the following best describes the conservation of angular momentum?

Accepted Answer

If no external torque acts on a system, its angular momentum remains constant.

Question 10

A diver jumps off a diving board. Which energy transformation occurs as the diver falls?

Accepted Answer

Potential energy is converted to kinetic energy.

Question 11

A 2 kg object moving at $$3\ \mathrm{m/s}$$ collides and sticks to a 1 kg object at rest. What is their final velocity after the collision?

Accepted Answer

$$v_f = \frac{(2\ \mathrm{kg} 	imes 3\ \mathrm{m/s}) + (1\ \mathrm{kg} 	imes 0)}{2\ \mathrm{kg} + 1\ \mathrm{kg}} = 2\ \mathrm{m/s}$$

Question 12

Which of the following statements about buoyant force is correct?

Accepted Answer

The buoyant force on an object is equal to the weight of the fluid displaced by the object.

Question 13

A sealed container of gas is heated at constant volume. What happens to the pressure inside?

Accepted Answer

The pressure increases.

Question 14

Which of the following best describes the Doppler effect?

Accepted Answer

A change in frequency or wavelength of a wave in relation to an observer moving relative to the source.

Question 15

Which property distinguishes sound waves from light waves?

Accepted Answer

Sound waves require a medium to travel; light waves do not.

Question 16

Which subatomic particle is responsible for the chemical properties of an atom?

Accepted Answer

Electron

Question 17

A 10 kg object is moving in a circle of radius 2 m at a speed of $$4\ \mathrm{m/s}. $$What is the magnitude of the centripetal force?

Accepted Answer

$$F_c = \frac{mv^2$}{r} = \frac{10\ \mathrm{kg} 	imes (4\ \mathrm{m/s})^2$}{2\ \mathrm{m}} = 80\ \mathrm{N}$$

Question 18

Which of the following is NOT a form of energy transformation?

Accepted Answer

Mass to velocity

Question 19

A person pushes a 50 kg box with a force of 200 N across a floor with a coefficient of kinetic friction $$\mu_k = 0.3. $$What is the frictional force?

Accepted Answer

$$f_k = \mu_k F_N = 0.3 	imes (50\ \mathrm{kg} 	imes 9.8\ \mathrm{m/s^2$}) = 147\ \mathrm{N}$$

Physics 107 – Final Exam Review: Comprehensive Study Notes

Study Guide - Practice Questions

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