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Exam I, Chapter 1-3 ~ Name:

G

Yllth

/tII

RIMes

Time: 1 hr. Max. points: 60. Show all your work. Give your answers with units.

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1) (10 Points)

(a) What, approximately, is the percent uncertainty for the measurement 8.7 m?

(b) What is the product of 12.35 and 1.25 written with the correct number of significant

figures?

(c) What is the difference between 103.5 and 102.24 written with the correct number of

significant figures?

(d) What is 56 +

l.216~5~o3.45

written with the correct number of significant figures? (e)

Can the velocity of an object be zero at the same instant its acceleration is not zero? (yes

or no) Give an example.

2) (10 Points) A car is moving along a road in such a way that the distance travelled is

given by s

=

a+bt +ct", where a=1.5 m, b=2.3 mis, and c=4.0 rn/s''. Derive

expressions for:

(a) the velocity and acceleration of the car as functions of time

(b) calcuate the values of the displacement, velocity, and acceleration of the car

at t=2 s and at t=10 s.

-? --;::t -?--;::t-?

3) (10 Points) Vectors

A

and 1J are shown in the figure. Vector

C

=

1J -

A.

Given magnitudes:

Pil

=16.0 units and

IBI

=7.00 units. Calculate the magnitude and

-?

direction (angle) for

C.

J

-

A