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MIDTERM STUDY GUIDE – PHYSICS 1
WARNING! This is only a guide in order to focus your studying effort. The midterm
will not be exactly like this. If it was, it would only be measuring your powers
of memorization, and you know how I despise that. The problems presented here
approximate those in the midterm, they do not mimic them. Please study over and
above that which is given here.
CONCEPTS
mathematical analysis
Proportion types, systematic vs. random uncertainty, accuracy, % error, metric conversions
1-D kinematics
scalar/vector, distance/displacement, speed/velocity, acceleration, kinematics graphs, freefall
relative motion/vector addition
frames-of-reference, vector addition (1 & 2 dimensions)
projectile motion
characteristics (horizontal = constant , vertical = accelerated), horizontal-vertical independence
dynamics
nature of force and its affect on motion, Newton's laws of motion, kinetic/static friction, air resistance & terminal
velocity, pulling/pushing at angle to motion, translational equilibrium, motion on an incline, Atwood machine
EXAMPLE PROBLEMS
1.
A car travels 10.0 km north in 400.0 s. Then it travels 25.0 km south in 850.0 s. What is the (a) average
speed and (b) average velocity of the car?
2.
A body with initial speed of 8.0 m/s moves along a straight line with constant acceleration and travels 640
m in 40.0 s. Find the (a) average velocity, (b) final velocity, and (c) acceleration.
3.
A truck starts from rest and moves with a constant acceleration of 5.0 m/s². Find its a) speed and b) the
distance traveled after 4.0 s has elapsed.
4.
A marble dropped from a bridge strikes the water in 5.0 s. Calculate (a) the speed with which it strikes
and (b) the height of the bridge.
5.
A baseball is thrown straight upward with a speed of 30.0 m/s. (a) How long will it rise? (b) How high will
it rise? (c) How long after it leaves the hand will it return to the starting point?
6.
A boat is pointed straight across a river (east) and is moving at a speed of 0.55 m/s relative to the water.
The current of the river is south at 0.30 m/s. (a) What is the velocity of the boat relative to the river bank?
(b) How long does it take the boat to cross the river if the river is 65 m wide?
7.
A ball, rolling with a speed of 20.0 cm/s, rolls off the edge of a table that is 80.0 cm high. (a) How long
does it take to drop to the floor? (b) How far, horizontally, from the table edge does the ball strike the
floor?
8.
A body projected upward from level ground at an angle 55 with the horizontal has an initial speed of
40. m/s. (a) How long does it remain in the air? (b) How far from the starting point will it strike?
9.
A force acts on a 2.0-kg mass and gives it an acceleration of 3.0 m/s². (a) What acceleration is produced
by the same force when acting on a mass of 4.0 kg? (b) How large is the force?
10.
A 95-kg box is sliding along a level floor with an initial speed of 15 m/s. (a) How large of a constant
frictional force is required to stop the box in a distance of 15 m? (b) What is the coefficient of friction
between the box and the floor?
11.
What is the weight of a 34.0 kg dog?
12.
A sign weighing 345 N is suspended in the manner shown below. Each rope makes an angle of 55˚ to
the vertical. Find the tension in each rope.
13.
A 22-kg wagon is pulled along the level ground by a rope inclined at 33 above the horizontal. A frictional
force of 31 N opposes the motion. How large is the pulling force if the wagon is moving with (a) constant
speed and (b) an acceleration of 0.40 m/s²?
14.
Find the accelerations and string tensions for each of the following systems:
a)
b)
(5.5 kg)
[ μ = 0.15 ]
(3.5 kg)
(4.0 kg)
(4.5 kg)
15.
A 15.0-kg suitcase slides down a loading ramp that makes an angle of 35 with the ground. If the
frictional force between the ramp and the suitcase is 66.8 N, find the magnitude of the acceleration of the
suitcase.
ANSWERS:
1) a. 28.0 m/s
b. 12.0 m/s, south
2) a. + 16 m/s
b. +24 m/s
3) a. 20. m/s
b. 40. m
4) a. 49 m/s
b. 120 m
5) a. 3.06 s
b. 45.9 m
6) a. 0.63 m/s, 29 S of E
7) a. 0.404 s
8) a. 6.7 s
c. 6.12 s
b. 120 s
b. 8.08 cm
b. 150 m
9) a. +1.5 m/s²
10) a. 710 N
c. +0.40 m/s²
b. 6.0 N
b. 0.77
11) 333 N
12) T1 = T2 = 300. N
13) a. 37 N
b. 47 N
14) a. a = 1.2 m/s² (clockwise)
T = 39 N
15) 1.17 m/s²
b. a = 3.3 m/s² (to the right & down)
T = 26 N