Conceptual Physics

C.11A truck full of corn is parked at x = 0 and is

pointed in the negative direction. If the driver

puts it into reverse and holds down on the

accelerator, will the following quantities be

positive, zero, or negative after one second?

(a) position, (b) velocity, (c) acceleration.

(a) i. Positive

ii. Negative

iii. Zero

(b) i. Positive

ii. Negative

iii. Zero

(c) i. Positive

ii. Negative

iii. Zero

C.12David is driving a minivan to work, and he is stopped at a red light. The light turns green and David drives to the next red
light, where he stops again. Is David's average acceleration from light to light positive, negative, or zero?
i. Positive
ii. Negative
iii. Zero

C.13If you know only the initial position, the final position, and the constant acceleration of an object, can you calculate the final

velocity? Explain.

Yes No

C.14A football is thrown vertically up in the air at 10 m/s. If it is later caught at the same spot it was thrown from, will the speed be

greater than, less than, or the same as when it was thrown? Ignore air resistance.

i. Greater than

ii. Less than

iii. Same

Section Problems

Section 0 - Introduction

0.1 Use the simulation in the interactive problem in this section to answer the following question. What kind of acceleration will
cause the hare to change directions?
i. Positive
ii. Negative
iii. Positive or negative

Section 1 - Position

1.1 Anita and Nick are playing tug-of-war near a mud puddle. They are each holding on to an end of a taut rope that has a knot
exactly in the middle. Anita's position is 6.2 meters east of the center of the puddle and Nick's position is 3.0 meters west of
the center of the puddle. What is the location of the knot relative to the center of the puddle? Treat east as positive and west
as negative.
meters

Section 2 - Displacement

2.1 A photographer wants to take a picture of a particularly interesting flower, but he is not sure how far away to place his

camera. He takes three steps forward, four back, seven forward, then five back. Finally, he takes the photo. As measured in

steps, what was his displacement? Assume the forward direction is positive.

step(s)

Copyright 2007 Kinetic Books Co. Chapter 2 Problems^45