Physics Department
Physics 101
First Midterm Exam
First Semester
Saturday, Oct 18, 2014
2:00 – 3:30 p.m.
Student’s Name: ………………..………………….…………………………………….…………
Student’s Number: ….……………………………………
Section: ……………………
Choose your Instructor’s Name:
Prof. Fikry El-Akkad
Dr. Hasan Raafat
Dr. Ahmed Al-Jassar
Dr. Hala Al- Jassar
Dr. Tareq Alrefai
Dr. Fatema Al-Dousari
For Instructors use only
Grades:
#
Dr. Yacob Makdisi
Dr. Abdul Khaleq
Dr. Abdul Mohsen
Dr. Nasser Demir
Dr. Belal Salameh
Q1
Q2
Q3
Q4
Q5
SP1
SP2
SP3
SP4
SP5
SP6
SP7
SP8
SP9
SP10
SP11
LP1
LP2
Total
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
20
Pts
Important:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Answer all questions and problems.
Full mark = 20 points as arranged in the above table.
i. 5 Questions
ii. 11 Short Problems
iii. 2 Long Problems.
No solution = no points.
Use SI units.
Check the correct answer for each question.
Assume g = 10 m/s2.
Mobiles are strictly prohibited during the exam.
Programmable calculators, which can store equations, are not allowed.
Please write down your final answer in the box shown in each problem.
GOOD LUCK
First Midterm – PHYS101
Part I: Questions (Choose the correct answer, one point each)
Q1. , and
are vectors as shown in the figure. The vector
*
*
Q2. * *
are non zero vectors. If .
*
*
0
1
is
*
0 then,
* *
*
Q3. If the velocity of a particle along the x-axis as a function of time is shown in the figure, then the
vx (m/s)
speed of the particle
* increases
* decreases
* constant
* increases and then decreases
* decreases and then increases
t(s)
Q4. A stone is thrown from the ground level at an angle of 30 ̊ above the horizontal. Its horizontal
range will be smaller if it is thrown with the same speed at an angle of
*0̊
* 40 ̊
* 50 ̊
* 60 ̊
* 70 ̊
y
Q5. A Ferris wheel with radius 12.0 m is turning clockwise about a
horizontal axis through its center. The linear speed of a passenger at
the rim is constant and equal to 6.0 m/s. The velocity (in m/s) and
the acceleration (in m/s2) of the passenger at the lowest point (A) are
respectively
*6 ̂and
x
* 6 ̂and3 ̂
3̂
* 6 ̂and
* 6 ̂and
3̂
* 6 ̂and3 ̂
10 ̂
A
Part II: Short Problems (1 point each)
SP1. After an airplane takes off, it travels 6.0 km east, 3.0 km north and 2.0 km up. How far (in km) is
the airplane from the take off point?
6
3
2
7
7
SP2. Vector
is shown in the figure. What are the x-and y-components of vector ?
SP3.
sin
5 0.6
5
3.0
y
37̊
cos
5 0.8
4.0
x
3.0
4.0
2
First Midterm – PHYS101
SP4. Two vectors
×
and
=6̂
have magnitudes A= 5.0 and B = 4.0.
8 ̂. What is the angle between the
Their vector product is
and ?
sin
6
8
10
30°
30°
vx(m/s)
SP5. A particle is moving along the x-axis, its position is given by
60
4
8
where x is (in m) and t is (in s).
2
Draw in the given diagram the velocity
6
of the particle
4
as a function of time.
4
4
t=0
V = ‒4
t=1
V=0
t=2
V=4
t=3
V=8
2
t (s)
‒2
1
2
3
4
5
‒4
SP6. A ball is thrown vertically upward with a speed of 15.0 m/s from the edge of a 20.0 m tall building.
The ball hits the ground 4.0 s later. Calculate the average velocity (in m/s) of the ball.
Vo = 15 m/s
5 /
∆
20 m
5
/
ground
SP7. A boy throws a ball straight up with an initial speed of 4.0 m/s. How long (in s) will take the ball
to return back to the boy’s hand?
∆
0
4.0
10 t = 0.8 s
0.8 s
SP8. With what constant acceleration (in m/s2) should a race car start from rest to reach a speed of
180 km/h in 20s.
180
50 /
⇒
2.5 /
2.5
/
3
First Midterm – PHYS101
SP9. The position vector (in m) of a squirrel running in a park is given by
0.30
0.04
What are
0.3
and
̂
0.02
̂
where t is (in s).
(in m/s) of the squirrel as functions of time?
0.08 m/s
0.06
m/s
0.3
0.08
0.06
m/s
SP10. A projectile is fired upward at an angle of 53.1 ̊ above the horizontal with an initial speed
5.0 / . Write down the velocity vector
v
(in m/s) and the acceleration vector
(in m/s2)
of the projectile at its maximum height in unit vector notations ̂ and ̂.
vo
v =
3.0
0 /
53.1̊
=
0
10 /
SP11. Passengers on a carnival ride move at constant speed in a horizontal circle of radius 5.0 m. With
what speed (in m/s) will the passengers rotate if the acceleration of the passengers is 3.2 m/s2?
3.2 5
4.0 /
4.0 /
SP12. A package falls out of an airplane that is flying horizontally in a straight line at a constant altitude
and speed. Draw the path of the package as observed by the pilot and the path as observed by a
person on the ground.
ground (2 Points each)
Part III: Long Problems
The path as observed
by the pilot
The path as observed
by the person
4
First Midterm – PHYS101
LP1. Car A leaves city A towards city B with a constant speed of 20 m/s. At the same instant, car B
leaves city B from rest towards city A with a constant acceleration of 0.1 m/s2. The two cars pass each
other 5 minutes later.
City B
City A
Find
d
a. the distance d (in km) between the two cities A and B.
20 300
6000
0
⇒
0.1 300
6.000
4500
4.500
10.5
10.5
b. the velocity (in m/s) of each car , at the instant they pass each other.
20 ⁄ 0
0.1 300
30 ⁄
20
⁄
30
⁄
c. the velocity (in m/s) of car A with respect to car B at the instant they pass each other.
20
30
50 /
50 /
LP2. A stone is thrown from the edge of a cliff (point A) with a speed of 5.0 m/s, at an angle of 53.1̊
above the horizontal. The stone strikes the ground at point C, 30 m from the base of the cliff.
Find
vo
a. the time of flight (in s) from point A to point C.
⇒ ∆
A
∆
10
h
10
b. the height of the cliff (h) (in m).
∆
4 10
40
460
C
10 10
500
30 m
460
cos
3.0 /
sin
4.0 /
460
5