Q: A projectile is launched at an angle $$\theta$$ above the horizontal with initial speed $$v_0. $$Which equation gives the maximum height reached by the projectile?

$$\frac{v_0$^2 \sin^2$\theta}{2g}$$

Q: A $$10\ \mathrm{kg}$$ mass is suspended from a steel wire. If the wire stretches by $$0.5\ \mathrm{mm}$$ under the load, what is the stress in the wire? (Assume $$g = 10\ \mathrm{m/s^2$}$$ and cross-sectional area $$A = 1\ \mathrm{cm^2$})$$

$$1 \times 10^6$\ \mathrm{N/m^2$}$$

Question 1

A car accelerates uniformly from rest to a velocity of $$20\ \mathrm{m/s} in$$ $$10\ \mathrm{s}. $$What is the magnitude of its acceleration?

Accepted Answer

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

Question 2

Which of the following is a vector quantity?

Accepted Answer

Displacement

Question 3

A projectile is launched at an angle $$	heta$$ above the horizontal with initial speed $$v_0. $$Which equation gives the maximum height reached by the projectile?

Accepted Answer

$$\frac{v_0$^2 \sin^2$	heta}{2g}$$

Question 4

A $$5\ \mathrm{kg}$$ box is pulled across a horizontal surface with a force of $$20\ \mathrm{N} at an $$angle of $$30^\circ$$ above the horizontal. If the coefficient of kinetic friction is $$0.2$$, what is the acceleration of the box?

Accepted Answer

$$2.4\ \mathrm{m/s^2$}$$

Question 5

Which of the following best describes Newton's Third Law?

Accepted Answer

For every action, there is an equal and opposite reaction.

Question 6

A $$2\ \mathrm{kg}$$ object moves with a velocity of $$3\ \mathrm{m/s}. $$What is its kinetic energy?

Accepted Answer

$$18\ \mathrm{J}$$

Question 7

A ball is dropped from a height $$h$$ and bounces back to a height $$0.8h. $$What fraction of its mechanical energy is lost during the bounce?

Accepted Answer

$$0.2$$

Question 8

A $$0.5\ \mathrm{kg}$$ ball moving at $$4\ \mathrm{m/s}$$ collides elastically with a stationary $$0.5\ \mathrm{kg}$$ ball. What is the velocity of the first ball after the collision?

Accepted Answer

$$0\ \mathrm{m/s}$$

Question 9

A solid disk of mass $$M$$ and radius $$R$$ rotates about its center with angular velocity $$\omega. $$What is its rotational kinetic energy?

Accepted Answer

$$\frac{1}{2} \left(\frac{1}{2} M R^2$\right) \$$omega^2$$

Question 10

A uniform beam is balanced at its center. If a $$10\ \mathrm{kg}$$ mass is hung $$2\ \mathrm{m}$$ from the pivot on one side, how far from the pivot should a $$5\ \mathrm{kg}$$ mass be hung on the other side to balance the beam?

Accepted Answer

$$4\ \mathrm{m}$$

Question 11

Which of the following statements about elastic collisions is correct?

Accepted Answer

Both kinetic energy and momentum are conserved.

Question 12

A satellite orbits Earth at a distance $$r$$ from the center of Earth. What is the expression for the gravitational force acting on the satellite?

Accepted Answer

$$\frac{G M m}{r^2$}$$

Question 13

A $$1\ \mathrm{m^3$}$$ block of wood floats in water with $$0.6\ \mathrm{m^3$}$$ submerged. What is the density of the wood?

Accepted Answer

$$600\ \mathrm{kg/m^3$}$$

Question 14

A force $$F is $$applied tangentially to a wheel of radius $$R. $$What is the resulting torque $$	au$$?

Accepted Answer

$$F R$$

Question 15

A $$10\ \mathrm{kg}$$ mass is suspended from a steel wire. If the wire stretches by $$0.5\ \mathrm{mm}$$ under the load, what is the stress in the wire? (Assume $$g = 10\ \mathrm{m/s^2$}$$ and cross-sectional area $$A = 1\ \mathrm{cm^2$})$$

Accepted Answer

$$1 	imes 10^6$\ \mathrm{N/m^2$}$$

Question 16

A car of mass $$m$$ moves at speed $$v$$ around a flat circular track of radius $$r. $$What is the minimum coefficient of friction $$\mu$$ required to prevent slipping?

Accepted Answer

$$\frac{v^2$}{r g}$$

Question 17

A diver of mass $$70\ \mathrm{kg}$$ jumps off a $$10\ \mathrm{m}$$ platform. Neglecting air resistance, what is the diver's speed just before hitting the water?

Accepted Answer

$$14\ \mathrm{m/s}$$

Question 18

A $$2\ \mathrm{kg}$$ object is attached to a string and swung in a horizontal circle of radius $$1.5\ \mathrm{m} at a $$speed of $$3\ \mathrm{m/s}. $$What is the tension in the string?

Accepted Answer

$$12\ \mathrm{N}$$

Question 19

Which of the following best describes the principle of conservation of mechanical energy?

Accepted Answer

The total mechanical energy of a system remains constant if only conservative forces act.

Question 20

A hydraulic lift has a small piston of area $$0.01\ \mathrm{m^2$}$$ and a large piston of area $$1\ \mathrm{m^2$}. If a $$force of $$100\ \mathrm{N} is $$applied to the small piston, what is the maximum weight that can be lifted by the large piston (neglecting friction)?

Accepted Answer

$$10,000\ \mathrm{N}$$

Physics I: Core Topics Overview and Chapter Structure

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