Name: _______________________________________________________
Signature:_____________________________________________________
Section:______________________________________________________
Answer all problems.
Do not start working until you are told to do so.
Following information may be useful:
formula sheets are also provided at the back of this test.
_________________________________________________________________________________________________________________________
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Circle the right answers. Only one choice is correct.
No penalty for wrong guess.
(note that there are several versions of the test.
You may have differenc choices for different versions.)
I. It is given that 1m has 100cm. 1 m3 equals to
A. 102 cm3
B. 10-2 cm3
C. 106 cm3
D. 10-6 cm3
E. None of above.
II. Calculate 10cm5m/2s in SI units:
A. 0.25 m2/s
B. 25 m/s
C. 0.25 m/s
D. 25 m2/s
E. Expression has no meaning, cannot be computed.
III. A pebble is dropped (from rest) into a dry water well, and it takes 3s for the pebble to reach the bottom. What is the distance from the rim of the well to the bottom?
A. 1.5m
B. 88.2m
C. 44.1m
D. 14.7m
E. 4.5m
IV. An object is performing linear constant (non-zero) acceleration motion. What are you sure about the motion?
A. The velocity must be changing all the time.
B. The velocity can never be zero.
C. Velocity and acceleration are always in the same direction.
D. The object cannot change its direction of travel.
E. The object must be traveling with an increasing speed.
V. A ballast bag of sand dropped (i.e. released from rest) from a hot-air balloon hits the ground at a certain speed and the craft slowly rises and soon comes to a stop. If a second identical bag is dropped and it its the ground twice as fast as the first, how high was the balloon when it was dropped in comparison to when the first bag fell?
A. ½ as high.
B. 2 times as high.
C. 
as high.
D. 
times as high.
E. 4 times as high.
2. (25 points)
In coming to a stop, a car leaves skid marks 120m long on the highway. Assuming a deceleration of 10.00 m/s2, estimate the speed of the car just before breaking.
Solution
'
a. (10 points)
How high will the object rise before it comes back down?
Solution
b. (5 points)
Where is the object when t=10s?
Solution
c. (5 points)
What is the average speed of the object from t=0s to t=10s?
Solution
d. (5 points)
What is the average velocity of the object between t=0s and t=10s?
(a) (15 points)
It takes how long for the ball to reach the ground?
Solution
(b) (5 points)
What must be the average speed of the person if she is to catch the ball at the bottom of the building (neglect the person's height).?
Solution
(c) (5 points)
What is the velocity of the ball when it is caught by the person?
Solution
I. Physical constants:
g = 9.8 m/s2 (on Earth's surface) G= 6.67 10-11 Nm2/kg2
II. Kinematics equations
III. Dynamics equations
IV. Momentum
VII. Circular motion
