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Unformatted text preview: Phylel/SIO/I—Iassam/Midterm I Name: (write name on every page) Signature: Section Number: Seat Number: 1. Closed Book. Only 1 sheet of paper (double sided) allowed
2. Put ﬁnal answers into the boxes provided. Show essential work next to box. 3. Use reverse sides for scratch work. 4. After you ﬁnish the exam, write and Sign the Honor Pledge in the box below:
“I pledge on my honor that l have not given or received any unauthorized assistance on this exam” g = 9.8 m/s.2 Maximum score Actual Score 1 —
— 4
5
7 1
— 1
— 2
TOTAL Problem 1 I Last Name: Four balls are thrown straight up from
Earth. The ﬁgure is a "snapshot" showing
their velocities. They have the same size, but different mass. Air resistance is
negligible. Rank in order, from largest to
smallest, the magnitudes of the net forces, 200 g
Fm 1, Fnetz, Fnct3, Fact 4, acting on the balls.
Some may be equal. Give your answer in
theforrnA>B=C>D. Sntfs 3 >9 > 27/ 7% my git/mg g 32> ” 7295! M0 Mair?!” 1””
(1L7 / 79” 25 WWI?) Problem 2 A car travels at constant speed along the curved path shown in
the ﬁgure below. Five possible vectors are also shown in the
ﬁgure; the letter B represents the zero vector. Which vector best represents the car's velocity at position 1?
Which vector best represents the car's velocity at position 2?
Which vector best represents the car's velocity at position 3?
Which vector best represents the car's acceleration at position 1?
Which vector best represents the car's acceleration at position 2?
Which vector best represents the car's acceleration at position 3? Problem 3 ‘ Last Name: You stand on a spring scale in an elevator sitting on the Earth and measure your weight to
be SOON. The same elevator, you are still on it, is now in interstellar space. You are in
between two stars, as shown. You are so far away from the stars (and any other masses)
that there is no gravitational forces on you. The elevator is moving towards one of the
stars, as shown by the arrow in the picture. What is your apparent weight (ie, what does  the scale measure) if
(a) you are moving at constant speed upwards at 2 m/s? (b) you are accelerating upwards at 2sz3—1— 2 57V 144/} 2 O 5791!» 0 star Problem 4 A car traveling at velocity v takes distance d to stop after the br es are applied. What is
the stopping distance if the car is initially traveling at velocity ? Assume that the acceleration due t the braking is the same in both cases. 2 V ) i; V) 3/
4A ﬁx L
, V 3 Z 65 4’
(Ed ﬁx Lﬂ/ Viz“ MW» / Problem 5 Last Name: A skier is gliding along at 5.0 m/s on horizontal, frictionless snow. He suddenly starts
down a 15° incline. His speed at the bottom is 14 m/s. (a) What is the length of the incline?
(b) How long does it take him to reach the bottom? (a) , _ a }
W l 0”) géig ~.
Mag—2.. Problem 6 Last Name: A 1.0 kg wood block is pressed against a vertical
wood wall by a 40 N force as shown in the ﬁgure.
Assume there is a kinetic friction force, f, for wood
on wood and that the magnitude of f = 0.1*n, where
n is the normal force. You are told that the block is sliding and accelerating upward. Find the
acceleration upward. or : Mia/5”?“ 5?” KW
I‘M/S" 7% SM '
£53 m/{l WM 74 “aw/40 _
' K0 @530 :7!” W3 Problem 7 Consider the system shown in Mass of A = 1kg, mass of B =j . There \/
is friction between A and the table, f = Mn, where mu = 0.5 and n is the normal force.
Find the acceleration of mass B. Last Name: String The tension in the string is the same on both sides .. ‘ of the pulley. Massless, a k.”
frictionless ...
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This note was uploaded on 12/28/2011 for the course PHYSICS 121 taught by Professor Shawhan during the Spring '10 term at Maryland.
 Spring '10
 Shawhan
 Physics

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