Final
Exam #1
Chapters
1-3
Mon,
5/9/11
Part 1
Lecture
Time: 1p.m. 2p.m.
1-10 _________________ (out
of 60)
11 _________________ (out
of 40)
Total _______________
Multiple
choice answer sheet-shade in correct answers below
(one choice per problem):
|
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
|
a |
|
|
|
|
|
|
|
|
|
|
|
b |
|
|
|
|
|
|
|
|
|
|
|
c |
|
|
|
|
|
|
|
|
|
|
|
d |
|
|
|
|
|
|
|
|
|
|
|
e |
|
|
|
|
|
|
|
|
|
|
1. An ant crawls north along a wall for 3.0
meters, then turns around and crawls 2.0 meters south back towards the starting
point. Find the total distance and the total displacement. (Take north as the
positive x direction.)
Distance Displacement
a.
1.0
m +1.0
m
b.
1.0
m -1.0
m
c. 3.0
m +2.0
m
d. 5.0
m +1.0
m
e.
5.0
m -
1.0 m
2. A
physics student rides her bike for 30 min covering a distance of 10 km, then
returns by a different route back to the starting point, covering an additional
15 km in an additional 30 min. What
was her average velocity?
a.
0 km/hr
b.
10 km/hr
c.
20 km/hr
d.
25 km/hr
e.
50 km/hr
3. At t = 0, the speed of an object
starting at x=0 and y = -10m is 40 m/s.
At t=5 sec., the particle is at x= -15m and y= 20m with a speed of 35
m/s.
Find
the average velocity over the time interval:
a. 22.9
m/s
b. 37.5
m/s
c. 3
m/s i -6 m/s j
d. -3
m/s i +2 m/s j
e. -3
m/s i +6 m/s j
4. A
lead ball is dropped off a cliff on Planet XXX where the acceleration due to
gravity is exactly 10 m/s2.
2 seconds later an identical lead ball is thrown straight down
from the same cliff with an initial speed of 30 m/s. Find the time measured from when
the first ball was released at which the balls are exactly side-by-side:
a. 3.0 s
b. 4.0 s
c. 5.0 s
d. 6.0 s
e. None of
the above
For problems 5-8, consider a rocket being
launched from rest straight up into the atmosphere of Planet XXX where the
acceleration due to gravity is exactly 10 m/s2. In the first stage,
the rocket accelerates at 20 m/s2 for 15 s. Then the motor cuts off and the rocket
continues to travel upwards for a while. (Ignore any effects due to air
resistance.)
5. Find the height of the rocket when the motor cuts off.
a. 75
m
b. 150
m
c. 1125
m
d. 2250
m
e. 4500
m
6. Find the speed of the rocket when the motor cuts off.
a. 150
m/s
b. 300
m/s
c. 2250
m/s
d. 4500
m/s
e. None
of the above
7. Find the height of the rocket at which it stops traveling upwards and begins to descend.
a. 1125
m
b. 2250
m
c. 3375
m
d. 4500
m
e. 6750
m
8. Find the total time the rocket is in the air before it hits the ground.
a. 8.8
s
b. 23.8
s
c. 66.2
s
d. 81.7
s
e. 148.5
s
9. Consider two trains running in the same
direction on parallel tracks. Train
1 passes the station at time, t = 0, with a constant speed of 100 m/s. Train 2
leaves the station 10 seconds later than train 1 at an initial speed of 0 m/s
but an acceleration of 20 m/s2. Find the
time, t, at which the trains are exactly
side-by-side:
a. 3.8
s
b. 13.1
s
c. 16.2
s
d. 26.2
s
e. 33.0
s
10. Let A = 5i - 6j, B = -10i + 7j, C = 2A – 3B
Write the vector, C, in vector notation:
a. 40i - 33j
b. 40i - 9j
c. -20i + 9j
d. -20i - 33j
e. None
of the above
11. A
hockey player launches a slap shot at the net from 15 m away at an angle with
the horizontal of 15o and with an initial speed of 30 m/s. The
height of the net is 1.22 m. Show your
work. (Note: use g = 9.81 m/s2).
a.
Calculate the initial x and y components of the hockey puckÕs initial
velocity and write the initial
velocity, vi, of the puck in vector form.
b.
Calculate the time in sec. that it will take for the puck to reach the
net.
c.
Determine whether the puck will enter the net or not-explain briefly why
or why not.
d. If
the net were not in place, calculate
the highest point the puck would reach.