Question 1

Which of the following is the current definition of the standard meter of length?

Accepted Answer

The distance traveled by light in a vacuum.

Question 2

How many significant figures are present in the number 0.003010?

Accepted Answer

4 significant figures.

Question 3

You walk 5.5 km to the north, then turn 60° to your right and walk another 4.5 km. How far are you from where you originally started?

Accepted Answer

$$6.4\ \mathrm{km}$$

Question 4

Given vectors $$\vec{A} = 3.00\ \hat{i} + 3.00\ \hat{j}$$ and $$\vec{B} = 3.00\ \hat{i} + 4.00\ \hat{j}$$, what is $$\vec{C} = \vec{A} + \vec{B}$$?

Accepted Answer

$$6.00\ \hat{i} + 7.00\ \hat{j}$$

Question 5

The position of an object as a function of time is given by $$x = b t^2$, where b = 2.0$$\ \mathrm{$$m/s^2$$}$$ and t$ is in seconds. What is the instantaneous velocity of the object when t = 2.2$$\ \mathrm{s}$$?

Accepted Answer

$$8.8\ \mathrm{m/s}$$

Question 6

A car accelerates from $$10.0\ \mathrm{m/s} to$$ $$30.0\ \mathrm{m/s} at a $$rate of $$3.00\ \mathrm{m/s^2$}. $$How far does the car travel while accelerating?

Accepted Answer

$$133\ \mathrm{m}$$

Question 7

A ball is spun in a circle with a radius $$20\ \mathrm{cm}$$ making $$7.00$$ revolutions every $$10.0$$ seconds. What is the magnitude of the acceleration of the ball?

Accepted Answer

$$8.79\ \mathrm{m/s^2$}$$

Question 8

You swing a bat and hit a heavy box with a force of $$1500\ \mathrm{N}. $$The force the box exerts on the bat is:

Accepted Answer

Exactly $$1500\ \mathrm{N}$$ whether or not the box moves.

Question 9

A $$50.0\ \mathrm{N}$$ box is sliding on a rough horizontal floor, and the only horizontal force acting on it is friction. You observe that the instant the box is sliding to the right at $$1.75\ \mathrm{m/s}$$ and that it stops in $$2.25\ \mathrm{s}$$ with uniform acceleration. What magnitude force does friction exert on this box?

Accepted Answer

$$39\ \mathrm{N}$$

Question 10

A $$10,000\ \mathrm{kg}$$ rocket blasts off from earth with a uniform upward acceleration of $$2.00\ \mathrm{m/s^2$}$$ and feels no air resistance. The upward thrust force it experiences must provide during this acceleration is:

Accepted Answer

$$118,000\ \mathrm{N}$$

Question 11

A $$60.0\ \mathrm{kg}$$ person rides in an elevator while standing on a scale. The elevator is traveling downward but slowing down at a rate of $$2.00\ \mathrm{m/s^2$}. $$The reading on the scale is closest to:

Accepted Answer

$$720\ \mathrm{N}$$

Question 12

A projectile is launched horizontally from a cliff. Which statement is true about its motion?

Accepted Answer

The horizontal component of its velocity remains constant and the vertical component of its acceleration is equal to $$-g.$$

Question 13

A uniform circular motion: A ball is tied to the end of a cable of negligible mass. The ball is spun in a circle at a radius $$20\ \mathrm{cm}$$ making $$7.00$$ revolutions every $$10.0$$ seconds. What is the magnitude of the acceleration of the ball?

Accepted Answer