CSULA PHYS
211 Summer’12
Chapter 2: Motion
in One Dimension Homework Assignment #1
Conceptual
Problems
1.
Driver A is cruising along enjoying the fall colors. Driver B
starts her car at the instant he passes her. Their velocities are shown as
functions of time in the graph below. At what instants in time on the graph are
drivers A and B side by side?
a.0 s, 2 s b.0 s, 4 s c.
2 s, 4 s
d.2 s, 6 s e.4 s, 6 s
2.
A
particle moving along the xaxis has a position given by x = (24t
– 2.0t3) m, where t is measured in s. What is the
magnitude
of the acceleration of the particle at the instant when its velocity is zero?
a. 24 m/s2b.0 c.12 m/s2d.48
m/s2 e.36 m/s2
Open-Ended Problems
3.Starting
from rest, a car travels 1,350 meters in 1.00 minute. It accelerated at 1.0m/s2
until it reached its
cruising speed. Then it drove the remaining distance at constant
velocity. What was its cruising speed?
4.A
car originally traveling at 30m/s manages to brake for 5.0 seconds while
traveling 125 m downhill. At that point the brakes fail. After an additional
5.0 seconds it travels an additional 150 m down the hill. What was the
acceleration of the car after the brakes failed?
5. A
speedy tortoise can run with a velocity of 10 cm/s and a hare can run 20 times
as fast. In a race, they both start at the same time, but the hare stops to rest
for 2.0 minutes. The tortoise wins by a shell (20 cm). What was the length of
the race?