Final Exam

1. Express 0.000000786 in standard notation

A. 7.86e-8
B. 7.86e8
C. 7.86e-6
D. 7.86e-7

2. One of the legs of a right angled triangle is 90 m. The angle opposite to this leg is 70 degrees. Calculate the length of the other leg.

A. 52.412 m
B. 32.757 m
C. 16.379 m
D. 22.93 m
E. 45.86 m

3. The following is the graph of position versus time for a certain particle.

On what interval(s) of time is it moving to the left.

A. 0-2 s, 4-8 s, and 10-14 s
B. 0-2 s, and 10-14 s
C. 4-8 s
D. 10-14 s
E. 0-8 s

4. An object was released from a height of 30 m. Its velocity just before it hits the ground and the time taken to hit the ground respectively are

A. -588 m ⁄ s and 6.122 s
B. -17.146 m ⁄ s and 1.75 s
C. -17.146 m ⁄ s and 2.474 s
D. -24.249 m ⁄ s and 2.474 s
E. -24.249 m ⁄ s and 1.75 s

5. Determine the x and y components of the vector A = 80 m east.

A. ( 0 m, 80 m )
B. ( -80 m, 0 m )
C. ( 0 m, -80 m )
D. ( 80 m, 80 m )
E. ( 80 m, 0 m )

6. A particle is displaced from the point ( -6 m, -2 m ) to the point ( -7 m, 7 m ). Calculate the magnitude of its displacement vector.

A. 5.099 m
B. 13.928 m
C. 82 m
D. 194 m
E. 9.055 m

7. Calculate the mass of an object whose weight is 1133 N.

A. 11.995 kg
B. 55.938 kg
C. 95.17 kg
D. 115.612 kg
E. 184.51 kg

8. An object of mass 24 kg is sliding down a friction less inclined plane that makes an angle of 30 deg with the horizontal. Calculate the component of gravitational force that pushes the object against the plane in a direction perpendicular to the inclined plane.

A. 235.2 N
B. 8.487 N
C. 203.689 N
D. 117.6 N
E. 4.9 N

9. Which of the following forces is not conservative?

A. Gravitational force
B. Electrical force
C. Force due to a spring
D. Friction
E. Magnetic force

10. Intially an object has a potential energy of 20 J and a kinetic energy of 130 J. Under the influence of conservative and non-conservative forces its potential energy changed to 5 J and its kinetic energy changed to 28 J. Calculate the net work done.

A. -94 J
B. -104 J
C. -102 J
D. -101 J
E. -99 J

11. An object moving with a speed of 0.2 m ⁄ s has a momentum of 2.4 kg m ⁄ s. Calculate its mass.

A. 3.415 kg
B. 16.427 kg
C. 20.051 kg
D. 12 kg
E. 13.524 kg

12. An object of mass 3 kg going to the right with a speed of 25 m ⁄ s collides with a(n) 6 kg object at rest. After collision the 3 kg object moves with a speed of 12 m ⁄ s making an angle of 40 degree with the horizontal-right. Calculate the x-component of the velocity of the 6 kg object after collision.

A. 3.217 m ⁄ s
B. 5.042 m ⁄ s
C. 2.023 m ⁄ s
D. 7.904 m ⁄ s
E. 12.476 m ⁄ s

13. Calculate the length of an arc subtended (opened) by a central angle whose radian measure is 2 rad in a circle of radius 11 m.

A. 4.257 m
B. 33.701 m
C. 22 m
D. 18.088 m
E. 10.142 m

14. Starting with an angular speed of 12 rad ⁄ s, an object was accelerated uniformly on a circular path of radius 0.8 m with an acceleration of 10 rad ⁄ s² for 3 s. Calculate its angular displacement.

A. 89.67 rad
B. 32.388 rad
C. 106.894 rad
D. 81 rad
E. 22.96 rad

15. Which of the following is a correct statement?

A. Moment of inertia of a particle decreases as the perpendicular distance between the axis of rotation and the particle increases.
B. Moment of inertia of an object does not depend on the mass of the object.
C. Moment of inertia of a particle is equal to the product of its mass and its perpendicular distance from the axis of rotation.
D. Moment of ineria of an object has the same value for different axis of rotations.
E. Moment of inertia of an object may have different values for different axis of rotations.

16. What is the condition for translational equilibrium?

A. the net force acting on the object should be zero.
B. the net torque acting on the object should be constant.
C. the net torque acting on the object should be zero.
D. the net force acting on the object should be constant.
E. the momentum of the object should be zero

17. Strain is physical quantity

A. used as a measure of deformation.
B. used as measure of the rotational effect of a force.
C. used as a measure of the amount of motion an object has.
D. used as a measure of a forces ability to deform an object
E. used as a measure of a forces ability to displace an object.

18. Two tubes of different cros-sectional areasare connected together horizontally. Which of the following is a true statement about a fluid flowing through the tubes.

A. The amount of fluid that leaves the wider tube is less than the amount of fluid that enters the narrower tube in the same interval of time.
B. The amount of fluid that leaves the wider tube is greater than the amount of fluid that enters the narrower tube in the same interval of time.
C. The pressure of the fluid in the narrower tube is greater than that in the wider tube.
D. The speed of the fluid in the narrower tube is less than the speed of the fluid in the wider tube.
E. The speed of the fluid in the narrower tube is greater than the speed of the fluid in the wider tube.

19. An aluminum rod has a length of 1.5 m at a temperature of 20 °C. What should its temperature be if its length is to increase by 0.007 m. (Coefficient of linear expansion for aluminum is 2.4e-5 ⁄ °C).

A. 300.19 °C
B. 214.444 °C
C. 261.951 °C
D. 373.677 °C
E. 339.903 °C

20. A 60 g sample of di-atomic Oxygen ( O₂ ) gas is at a temperature of 100 °�C. Calculate the RMS (root mean square) speed of the molecules of the sample. (atomic mass of Oxygen is 16 u. )

A. 216.033 m ⁄ s
B. 295.949 m ⁄ s
C. 538.74 m ⁄ s
D. 702.191 m ⁄ s
E. 451.912 m ⁄ s

21. A bullet of mass 0.025 kg was fired into an aluminum metal (specific heat capacity 900 J ⁄ kg ⁄ °C) of mass 2 kg with a speed of 650 m ⁄ s. If half of the kinetic energy of the bullet is transferred to the aluminum metal as heat energy, by how much would the temperature of the aluminum metal increase?

A. 0.703 °C
B. 2.66 °C
C. 1.467 °C
D. 1.282 °C
E. 1.851 °C

22. Radiation is a way of transfer of heat

A. by means of collisions of neighboring molecules.
B. by means of the actual movement molecules.
C. by means of movement of air molecules.
D. by means of diffusion.
E. by means of propagation of electromagnetic waves.

23. The following is a PV dagram for a certain system of gas.

Calculate the work done in taking the system from the point D( 2 L, 4 kPa) to the point B( 6 L, 2 kPa) along path DCB.

24. Which of the following statements is not a correct statement.

A. The entropy of an isolated system can only increase.
B. The efficiency of a heat engine can be as high as a 100%.
C. The gas state has more entropy than the liquid state.
D. An isolated system can only proceed from order to disorder.
E. The entropy of the universe can only increase.