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?

$$\displaystyle H = \frac{v_0$^2 \sin^2$\theta}{2g}$$

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

$$2.0\ \mathrm{m/s^2$}$$

Question 2

Which of the following best describes the difference between scalar and vector quantities?

Accepted Answer

Vectors have both magnitude and direction; scalars have only magnitude.

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

$$\displaystyle H = \frac{v_0$^2 \sin^2$	heta}{2g}$$

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

$$1.6\ \mathrm{m/s^2$}$$

Question 5

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

Accepted Answer

Newton's First Law

Question 6

A $$2\ \mathrm{kg}$$ object moves in a circle of radius $$4\ \mathrm{m} at a $$constant speed of $$3\ \mathrm{m/s}. $$What is the magnitude of the net force acting on the object?

Accepted Answer

$$6.0\ \mathrm{N}$$

Question 7

A $$0.5\ \mathrm{kg}$$ ball is dropped from a height of $$10\ \mathrm{m}. $$What is its kinetic energy just before hitting the ground? (Neglect air resistance.)

Accepted Answer

$$50\ \mathrm{J}$$

Question 8

Which of the following is true about the conservation of mechanical energy in a system with only conservative forces?

Accepted Answer

Mechanical energy is constant.

Question 9

A $$1\ \mathrm{kg}$$ ball moving at $$4\ \mathrm{m/s}$$ collides elastically with a stationary $$1\ \mathrm{kg}$$ ball. What is the velocity of the first ball after the collision?

Accepted Answer

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

Question 10

A solid disk and a hoop, both of mass $$M$$ and radius $$R$$, roll without slipping down an incline. Which reaches the bottom first and why?

Accepted Answer

The disk, because it has less rotational inertia.

Question 11

A uniform beam is supported at its ends. A $$10\ \mathrm{kg}$$ mass is placed $$2\ \mathrm{m}$$ from the left end of a $$6\ \mathrm{m}$$ beam. What is the upward force at the right support?

Accepted Answer

$$66\ \mathrm{N}$$

Question 12

Which equation correctly expresses Newton's Law of Universal Gravitation?

Accepted Answer

$$F = G\frac{m_1$ m_2$}{r^2$}$$

Question 13

A hydraulic lift uses a small piston of area $$0.01\ \mathrm{m^2$}$$ and a large piston of area $$0.5\ \mathrm{m^2$}. If a $$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

$$5000\ \mathrm{N}$$

Question 14

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 $$4\ \mathrm{m/s}. $$What is the tension in the string?

Accepted Answer

$$21.3\ \mathrm{N}$$

Question 15

A diver of mass $$60\ \mathrm{kg}$$ jumps off a $$10\ \mathrm{m}$$ platform. What is her speed just before hitting the water? (Neglect air resistance.)

Accepted Answer

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

Question 16

A $$0.2\ \mathrm{kg}$$ ball moving at $$5\ \mathrm{m/s}$$ strikes a wall and rebounds at $$3\ \mathrm{m/s} in $$the opposite direction. What is the magnitude of the impulse delivered to the ball?

Accepted Answer

$$1.6\ \mathrm{kg\cdot m/s}$$

Question 17

A $$3\ \mathrm{kg}$$ mass is attached to a spring with a force constant $$k = 150\ \mathrm{N/m}. $$What is the period of oscillation?

Accepted Answer

$$1.41\ \mathrm{s}$$

Question 18

A $$1.5\ \mathrm{kg}$$ object floats in water with $$0.5\ \mathrm{kg} of $$its mass submerged. What is the buoyant force acting on the object?

Accepted Answer

$$4.9\ \mathrm{N}$$

Question 19

A $$10\ \mathrm{kg}$$ mass is suspended from the center of a horizontal uniform beam of length $$4\ \mathrm{m}$$ and mass $$6\ \mathrm{kg}. $$What is the tension in the cable supporting one end if the other end is hinged to a wall?

Accepted Answer

$$58.8\ \mathrm{N}$$

Physics I: Core Topics Overview

Guida di studio - Domande di pratica

Study guide - Flashcard