# Physics Exam: Potential Energy And Conservation Of Energy! Quiz

20 Questions | Total Attempts: 54

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• 1.
A block of mass m is pulled at a constant velocity along a horizontal rough surface by an applied force T=20N  the angel θ=37 .The magnitude of friction force in N is
• A.

16

• B.

40

• C.

48

• D.

24

• E.

32

• 2.
The position of a particle moving on the X-axis is given X(t)=4t-3.0t3. Where X is displacement in m and t is time in s . At what time will the particle has zero velocity ?
• A.

0.67 s

• B.

1.33 s

• C.

1.67 s

• D.

1 s

• 3.
A projectile is thrown from ground at an angel of θ=30ْ  above the horizontal and an initial speed of 500m/s calculate the horizontal distance in m/s
• A.

86.6

• B.

21.7

• C.

13.5

• D.

65.3

• E.

48.7

• 4.
As in the figure shown the mass m=1kg sit on a vertical compressed spring where the distance of compression is 20 cm . What is the maximum height from release  point does the mass m reach (k=2000N/m)?
• A.

2m

• B.

10m

• C.

4m

• D.

20m

• 5.
A gun is aimed horizontally at a center of a large target at a center of a large target 60 m way . The bullet starts at an initial velocity of 240m/s  . When the bullet strikes , the distance from the center of the target to the place where the bullet strikes is :-
• A.

0.60

• B.

1.25

• C.

0.31

• D.

0.45

• 6.
A 0.2kg bullet is fired horizontally on a colonial pendulum as shown in the figure with speed of 200m/s  on a ballistic pendulum of mass 4kg . If the bullet embedded in the pendulum how high will the system rise in m ?
• A.

4.6

• B.

5.5

• C.

6.5

• D.

3.7

• 7.
A three- particles system of equal masses. The first particle is located at (8,-4) m and the second particle at ( 0,6) and the third at (-2,-4). What is the position of the center of mass of the system in (m)?.
• A.

(0.5 , 0.5)

• B.

(3.1 , 3.1)

• C.

(2 ,  -0.7)

• D.

(0.3 , 0.2 )

• 8.
A 4.0-kg object is attached to the end of a string rotates in a circular motion on a horizontal frictionless table. The mass has a constant speed of 2.0 m/s and the radius of the circle is 0.80 m. What is the magnitude of the tension in the string in N ?
• A.

32

• B.

20

• C.

40

• D.

80

• 9.
A solid sphere (radius R, mass M) rolls without slipping down an incline with    inclination angle of θ=37 . The linear acceleration of its center of mass(in m/s ) is: (I = 2mR2/5)
• A.

5.7

• B.

3.6

• C.

4.3

• D.

6.2

• 10.
A 2 kg ball slides from rest on the frictional track shown from a height h = 4 m. If the speed (in m/s) of the ball at the bottom of the track is 6 m/s, what is the work done by the friction (in J):
• A.

-86

• B.

-64

• C.

-44

• D.

-104

• E.

-96

• 11.
The bar in the figure is subject to the forces shown. If the bar has length of 1.2 m, what is the net torque about the center of the bar (in N m)?
• A.

4.8

• B.

4.3

• C.

2.9

• D.

3.8

• E.

5.2

• 12.
] A uniform rod of length L and mass M in a horizontal position is free to rotate about one of its end. If the rod is released from rest find its angular velocity when the rod reaches the vertical position.  Given that Ic.m = (1/12)ML2
• A.

(glL)1/2

• B.

(2glL)1/2

• C.

(3glL)1/2

• D.

(4glL)1/2

• E.

(5glL)1/2

• 13.
A wheel rotates with a constant angular acceleration of 2.5 rev/s2. During a certain time interval its angular displacement is 3 revolutions. At the end of the interval its angular velocity is 4 rev/s. Its angular velocity at the beginning of the interval is:
• A.

3.2

• B.

1

• C.

5.8

• D.

2·4

• E.

4.6

• 14.
) The block shown is released from rest when the spring is stretched a distance d. Given that k = 50 N/m, m = 0.25 kg, d = 10 cm, and μk = 0.5, determine the kinetic energy of the block when it first passes through the position of equilibrium in Jol
• A.

0.3

• B.

3.3

• C.

1.0

• D.

0.13

• 15.
) A car has a mass of 400 kg when fully loaded with passengers. The car passes over a hill of radius 10 m, as shown. At the top of the hill, the car has a speed of 10 m/s. What is the force of the track on the car at the top of the hill?
• A.

0.0 kN

• B.

7.0 kN down

• C.

2.8 kN down

• D.

2.8 kN up

• 16.
Two disks rotate about a common axis. The two disks are slowly forced toward each other until they stick together and have a final common angular velocity with a magnitude of:
• A.

ω

• B.

1/5ω

• C.

7/3ω

• D.

3/2ω

• E.

7/5ω

• 17.
At t = 0, a wheel rotating about a fixed axis at a constant angular acceleration of –0.40 rad/s2has an angular velocity of 1.5 rad/s and an angular position of -2.7 rad. What is the angular position of the wheel at t = 2.0 s?
• A.

• B.

• C.

• D.

• 18.
) The rigid body shown is rotated about an axis perpendicular to the paper and through the point P. If M = 0.40 kg, a = 30 cm, and b = 50 cm, how much work is required to take the body from 3.0 rad/s angular speed to 5.0 rad/s? Neglect the mass of the connecting rods and treat the masses as particles
• A.

2.5 J

• B.

3.5 J

• C.

1.7 J

• D.

2.6 J

• 19.
) If A = 5.0, B = 9.0, and α = 28°, determine the scalar product of the two vectors shown.
• A.

+35

• B.

+40

• C.

–40

• D.

-35

• 20.
The figure shows a uniform, horizontal beam (length = 10 m, mass = 25 kg) that is pivoted at the wall, with its far end supported by a cable that makes an angle θ with the horizontal. If a person (mass = 60 kg) stands 3.0 m from the pivot, find θ given that the tension in the cable is 0.4 kN
• A.

30ο

• B.

40ο

• C.

70ο

• D.

50ο

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