Benchmark 1 Review p.1
Name_______KEY____________________Period_________Date____________
CP Physics – Benchmark 1 - Review
Test Date:______________
1. Merck decides to test a new antibiotic to see if it will cure patients’ sinus
infections. Some testers are given pills containing the new antibiotic and
others are given a placebo, or sugar pill.
Identify the:
a. Control
 Placebo (no experimental treatment)
b. Independent Variable
 Which pill patients receive
c. Dependent Variable
 How well the patients feel afterward
2. Perform the following metric conversions:
a. 25mL = ?daL
 0.0025 daL
b. 874kg = ?g
 874,000 g
c. .535hm = ?cm
 5350 cm
3. What is the speed of a car that travels 300. miles in 5 hours?

d
300. miles
t
5 hr
v= =
= 60 mph
4. A cat runs at 2 m/sec. how far will the cat get in 35 seconds?
 d = v ‧ t = (2 m/sec)(35 seconds) = 70 m
Benchmark 1 Review p.2
5. What is acceleration? What is the acceleration of a car that moves from rest
to 22 m/s in 5 seconds?

a=
v2 – v1
t
=
22 m/s – 0 m/s
5 sec
= 4.4 m/s2
6. What does a flat line on a position vs. time graph mean? A straight, sloped
line?
 Flat line – no motion, no speed
 Straight, sloped line – constant speed, no acceleration
7. What kind of speed is represented in the graph below? What is the value of
the speed? Make a rough sketch of the position vs. time graph.
The graph represents accelerated speed. The acceleration is 10 m/s2.
8. What kind of acceleration does the object have in the diagram below?
The object has negative or deceleration.
9. Does it take more force to stop a bowling ball or a tennis ball? Why?
 The Bowling ball takes more force because it has more mass. The
more mass, the more inertia, the more force needed to change motion.
10.A helicopter’s speed increases from 0 m/s to 25 m/s in 5 seconds. Calculate
its acceleration.
 a=
v2 – v1
t
=
25 m/s – 0 m/s
5 sec
= 5 m/s2
Benchmark 1 Review p.3
11.A force of 500-N propels a 1000-kg train down a track. If a frictional force
of 200 N acts on the train determine the (a) the net force acting on the train
and (b) the acceleration of the train and the direction the train is accelerating.
 a. Fnet = Fapp – Ff = 500 N – 200N = 300N
 b. A =
F
m
=
300 N
1000 kg
= 0.3 m/s2
12. What is Newton’s 3rd law of motion?
 For every action, there is an equal and opposite reaction. Forces come
in pairs.
13. If Brandon drops a penny off the top the school and it hits the ground 5
seconds later, how tall is the school? (d=4.9t2)
 d = ½ (9.8 m/s)t2 = ½ (9.8 m/s)(5 s)2 = 123 m
14. What is terminal speed?
 The maximum speed reached in free fall. Fair = Fg .
15. What is the momentum of a 200 kg motorcycle travelling at 15 m/s?
 p = mv = (200 kg)(15 m/s) = 3,000 kg ∙ m/s
16. Give examples of elastic and inelastic collisions.
 Elastic – pool balls colliding, electrons colliding
 Inelastic – car crashes, egg falling to ground
17. How do you find the velocity of the combined objects in an inelastic
collision?
 Add up momentum for both objects before crash, combine masses and
solve for speed
 m1v1 + m2v2 = (m1 + m2) v3
Benchmark 1 Review p.4
18. In the image to the right, at what points are potential
and kinetic energy highest, lowest, and equal?
 KE – highest at 1, lowest at 3
 PE – highest at 3, lowest at 1
 KE = PE at height 2
19. As an object falls due to gravity, does it gain or lose
potential energy and does it gain or lose kinetic energy?
Why?
 As an object falls, it loses PE and gains KE because the PE is
converted to KE.
20. Calculate the kinetic energy of a 3 kg object moving at 5 m/s.
 KE = ½ mv2 = ½ (3 kg)(5 m/s)2 = 37.5 J
21. If the object in question 20 were moving straight up, what height would it
reach?
 KE = PE; h = PE / mg = (37.5 J) / [(3 kg)(9.8 m/s2)] = 1.28 m
22. How is weight different than mass? What is the formula for weight?
 Weight is the effect of gravity upon an object. Fg = mg.
23. Julie Joule and Nellie Newton both climb 3 steps. Julie has a mass of 60kg
and Nellie a mass of 50kg. Julie climbs the steps in 3s and Nellie climbs
them in 2s.
a. Who does more work?
 JJ : W = F ∙ d = [(60 kg)(9.8 m/s2)] * 3 m = 1764 J – most work
 NN: W = F ∙ d = [(50 kg)(9.8 m/s2)] * 3 m = 1470 J
b. Who uses more power?
 JJ: P = W / t = 1764 J / 3 s = 588 W
 NN: P = W / t = 1470 J / 2 s = 735 W – most power
24.What is the net force on the object below? Calculate the acceleration of the
object below and indicate the direction the object is accelerating.
 Fnet = Fa – Ff = 70 N – 20 N = 50 N to the right
 A=
F
m
=
50 N
10 kg
= 5 m/s2
Benchmark 1 Review p.5
25.Two chains are used to lift a small boat weighing 1500 newtons. As the boat
moves upward at a constant speed, one chain pulls up on the boat with a
force of 600 newtons. What is the force exerted by the other chain?
 Fup = Fdown
 1500 N = 600 N +Ft
 Ft = 900 N
26.Stephanie pushes a box with 5 newtons of force toward the east. Alexa pulls
on the same box with a force of 7 newtons toward the south. Calculate the
magnitude of the wagon’s resultant force. (Hint: Pythagorean’s theorem)
 a2 + b2 = c2; c = √[(5 N)2 + (7 N)2] = 8.6 N
27.A spring has a spring constant of 100 N/m. What force does the spring exert
on you if you stretch it a distance of 0.5 meters? (F=-kx)
 F = kx = (100 N/m)(0.5 m) = 50 N
28.Friction always __opposes______ the direction of motion.