PHYS 100  Midterm examination #1 (vers. 1B)

 

Spet. 30, 2005                                            Name________________________________

Time: 50 minutes                                                    Student No.___________________________

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Part I  (Multiple choice questions).  For each of the following five questions, please circle one answer only.

 

1(2/20).   The moon travels about 2.4´106 km in 28 days in one rotation around the earth. Express its speed in meters per second.

A)  9.9 ´ 105  m/s

B)  5.8 ´ 1015  m/s

C)  9.9 ´ 102  m/s

D)  5.8 ´ 1012  m/s

E)  8.5 ´ 104  m/s

 

2(2/20).  A student holds a pencil vertically at arm’s length.  The pencil just obscures the student’s view of a distant water tower. The pencil-to-eye distance is 50cm and the pencil is 8cm long.  If the tower is 80 meters high, how far away is the tower from the student? 

A)  500 m

B)  50 m

C)  128 m

D)  1280 m

E)  5000 m

 

Please refer to the following position-versus-time graph when answering questions 3-5:

D
 

C
 

A                                                            A
 

B
 

3(2/20).  The displacement that occurs in time interval D is

A)   Positive

B)    0

C)    Increasing

D)   Negative

E)    Equal to the instantaneous velocity

 

4(2/20).  The average velocity in time interval A is

F)    Increasing

G)   0

H)   Positive

I)      Negative

J)     Decreasing

 

5(2/20).  During time interval C the instantaneous velocity is

K)   Positive

L)    0

M)  Increasing

N)   Negative

O)   Equal to the average velocity

 

 

Part II  (Full solution questions).  For questions 6 and 7, please show complete solutions and explain your reasoning, stating any principles that you have used.

 

6(5/20).  You are driving through town at 12.0 m/s when suddenly a ball rolls out in front of you. You apply the brakes and begin slowing down at 4.00 m/s2.

a) How far do you travel before stopping?
b) What is your speed when you have traveled only half the distance ?

 

 

7(5/20).  A boy throws a small ball upward into the air with an initial velocity of 10.0 m/s.

a)  Find the maximum height that the ball reaches?
b)  How long, in seconds, is the ball in the air before it comes back to the boy’s hand?