Question 1

A car moves east with a velocity of $$20\ \mathrm{m/s}$$ and then accelerates at $$2\ \mathrm{m/s^2$}$$ for $$5$$ seconds. What is its final velocity?

Accepted Answer

$$30\ \mathrm{m/s}$$

Question 2

Which of the following statements about displacement is correct?

Accepted Answer

Displacement is a vector quantity and can be positive or negative depending on direction.

Question 3

A ball is thrown vertically upward with an initial velocity of $$15\ \mathrm{m/s}. $$Ignoring air resistance, what is its velocity after $$2$$ seconds? (Take $$g = 9.8\ \mathrm{m/s^2$}$$ downward.)

Accepted Answer

$$-4.8\ \mathrm{m/s}$$

Question 4

Which equation correctly relates average velocity $$v_{avg}$$, displacement $$\Delta x$$, and time interval $$\Delta t$$?

Accepted Answer

$$v_{avg} = \frac{\Delta x}{\Delta t}$$

Question 5

A projectile is launched at an angle $$	heta$$ with initial speed $$v_0. $$What is the formula for its initial vertical velocity component?

Accepted Answer

$$v_{0y} = v_0$ \sin 	heta$$

Question 6

On a position vs. time graph, what does a straight, non-horizontal line indicate?

Accepted Answer

Constant velocity

Question 7

A $$5\ \mathrm{kg}$$ box is at rest on a horizontal surface. What is the normal force acting on the box?

Accepted Answer

$$49\ \mathrm{N}$$

Question 8

Which of the following best describes Newton's First Law of Motion?

Accepted Answer

An object at rest stays at rest, and an object in motion stays in motion unless acted on by a net external force.

Question 9

A $$10\ \mathrm{kg}$$ object is pulled with a net force of $$30\ \mathrm{N}. $$What is its acceleration?

Accepted Answer

$$3\ \mathrm{m/s^2$}$$

Question 10

A boat moves across a river with a velocity of $$\vec{v}_{A/B}$$ relative to the water, and the water flows with velocity $$\vec{v}_{B/C}$$ relative to the shore. What is the boat's velocity relative to the shore?

Accepted Answer

$$\vec{v}_{A/C} = \vec{v}_{A/B} + \vec{v}_{B/C}$$

Question 11

A $$2\ \mathrm{kg}$$ block slides down a frictionless incline at $$30^\circ. $$What is the component of gravitational force parallel to the incline?

Accepted Answer

$$9.8\sin 30^\circ = 4.9\ \mathrm{N}$$

Question 12

Which of the following is a correct statement about vectors?

Accepted Answer

Vectors have both magnitude and direction.

Question 13

A $$3\ \mathrm{kg}$$ object is moving with velocity $$4\ \mathrm{m/s}$$ east. What is its momentum?

Accepted Answer

$$12\ \mathrm{kg\cdot m/s}$$\ east

Question 14

If a force of $$10\ \mathrm{N} is $$applied to a $$2\ \mathrm{kg}$$ object at rest on a frictionless surface, what will be its velocity after $$3$$ seconds?

Accepted Answer

$$15\ \mathrm{m/s}$$

Question 15

Which graph best represents an object moving in the positive direction and speeding up?

Accepted Answer

Graph C

Question 16

A $$1\ \mathrm{kg}$$ ball is dropped from rest. What is its velocity after $$2$$ seconds? (Ignore air resistance, $$g = 9.8\ \mathrm{m/s^2$})$$

Accepted Answer

$$19.6\ \mathrm{m/s}$$\ downward

Question 17

Which of the following is the correct formula for the magnitude of the resultant vector $$R$$ from components $$R_x$$ and $$R_y$$?

Accepted Answer

$$R = \sqrt{R_x^2$ + R_y^2$}$$

Question 18

A $$10\ \mathrm{kg}$$ box is pulled across a floor with a force of $$50\ \mathrm{N} at an $$angle of $$30^\circ$$ above the horizontal. What is the horizontal component of the force?

Accepted Answer

$$50\cos 30^\circ = 43.3\ \mathrm{N}$$

Kinematics and Newton's Laws: Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard