UIC Physics 105 Summer 2011 Midterm Practice Exam Physics 105 Midterm Practice Exam
LAST Name (print)*: _________________________________
FIRST Name (print)*: ________________________________
Signature*: ________________________________________
UIN #*: ____________________________________________
* Please fill in all required fields PROBLEM
POINTS
1
20
2
15
3
15
4
15
5
20
6
15
TOTAL
100
SCORE
Giving or receiving aid in any examination is cause for dismissal from the University.
Any other violation of academic honesty can have the same effect.
Perform the necessary calculations in the space provided
ALL WORK MUST BE CLEARLY SHOWN TO RECEIVE FULL CREDIT, NO CREDIT
WILL BE GIVEN IF NO WORK IS SHOWN.
1 UIC Physics 105 Summer 2011 Midterm Practice Exam Problem 1 (20 points)
Once upon a time, a famous zoologist was hunting antelope for a zoo with a dart gun
that fired darts with a range of 100 m at a speed of 25 m/s. If he shot a dart at an
antelope at rest 50 m away, and the antelope instantly began to accelerate at a
constant rate away from the dart, running out of range of the dart just in time.
a) [5 points] Find the minimum acceleration of the antelope; (10 points).
b) [10 points] Find the maximum time the antelope can remain in range of the dart.
c) [5 points] Find the minimum speed of the antelope as it runs out of range of the dart.
2 UIC Physics 105 Summer 2011 Midterm Practice Exam Problem 2 (15 points)
A kitten jumps off a table and lands on the floor. The height of the table is h = 85 cm.
The kitten begins his jump with an initial speed of ࢜૙ = 5.0 m/s at an angle of θ0 = 53o
above the horizontal.
a) [5 points] Find the maximum height,
hmax, that the kitten attains.
b) [5 points] How long does it take for him to reach the floor?
c) [5 points] How far away does the kitten land from his starting point?
3 UIC Physics 105 Summer 2011 Midterm Practice Exam Problem 3 (15 points)
Two blocks are connected by a spring and a cord as shown in the Figure, with the
spring connected to a wall. Initially, the spring is neither stretched nor compressed. The
gorizontal surface and the pulley are frictionless. The masses of the blocks are m1 = 20
kg, and m2 = 30 kg. Block 2 is hanging at a height h = 75 cm above the ground. The
spring constant is k = 400 N/m. The
masses are released from rest.
a) [5 points] What is the tension in the
string just before the block 2 hits the
ground?
b) [10 points] Find the speed the blocks will have just as block 2 strikes the ground.
4 UIC Physics 105 Summer 2011 Midterm Practice Exam Problem 4 (15 points)
A 2.00 kg particle moves along an x axis in one-dimensional motion while a
conservative force along that axis acts on it. The potential energy U(x) associated with
the force is plotted in Figure. When the particle is at x = 5 m, its velocity is 1 m/s.
a) [5points]
What is the particle’s speed at x = 0?
b) [10 points]
Calculate the force acting on the particle when it is in the region 1.5<x<2.5 m.
5 UIC Physics 105 Summer 2011 Midterm Practice Exam Problem 5 (20 points)
A block of mass m = 1 kg slides along a smooth track from one level to a higher level
after passing through an intermediate valley. The higher level has a rough section of
length L = 40 cm. After passing this section the block slides head on into a spring. The
block momentarily stops after compressing the spring by d = 7.5 cm. The block initial
speed v0 is 5.0 m/s, the height difference h is 1.0 m and the coefficient of kinetic friction
μ is 0.5.
a) [10 points] Find the block’s velocity when it reaches the higher level.
b) [10 points] Determine the spring constant k.
6 UIC Physics 105 Summer 2011 Midterm Practice Exam Problem 6 (15 points)
A ball moving in the x direction strikes
another ball of the same mass that is
initially at rest. The first ball moves off
in a direction θ1,f = 37o above the xaxis. The second ball moves off in a
direction θ2,f = 53o above the x-axis.
a) [10 points] Find the percentage of
the kinetic energy that the first ball
carries away after the collision. [Hint:
Find the ratio of v1,f to v2,f]
b) [5 points] Demonstrate that this is an elastic collision.
7