PHYSICS MOCK 2

17. A solid whose volume is 12 𝑚3 and weighing 950 kg is dropped into a pool of fresh water. The weight of the water it displaces is greater than 950 kg. Which of the following will happen? a. The solid will float. b. The solid will sink. c. The solid will be suspended. d. The solid will float then sink.

A

25. A heavy stone and a light feather were dropped inside a vacuum chamber from the same height at the same time. Which of the following statements about the situation is FALSE? I. In the vacuum, equal forces of gravity act on both the stone and the feather. II. The two objects will reach the bottom of the chamber at the same time. III. Air resistance is not present and so the two objects accelerate at the same rate. IV. The two objects have equal masses and equal weights. a. I and IV c. IV only b. II and III d. All are true

A

3. A Carnot refrigerator takes heat from water at 0˚C and rejects heat to a room at 27˚C. If 50 g of water at 0˚C is converted to ice at 0˚C, how much energy must be supplied to the refrigerator? a. 4.60 × 10-4 kwh c. 4.00 × 10-5 kwh b. 3.90 × 10-4 kwh d. 2.62 × 10-5 kwh

A

32. Jaja shoots a projectile from a gun making an angle of 450 with the horizontal. The initial velocity of the bullet is 100 m/s. Assume that g = 10 m/s2. After 5 seconds, what is the bullet's acceleration along the x-axis? a. 0.00 m/s2 c. 96.6 m/s2 b. 10.0 m/s2 d. 100.00 m/s2

A

42. Princess is cooking a pot roast for dinner in a pressure cooker. Water will normally boil at a temperature of 373 K and an atmospheric pressure of 1.01 x 105 Pa. What is the boiling temperature inside the pot, when the pressure is increased to 1.32 x 105 Pa? The pot maintains a constant volume. a. 200 0C b. 20.0 0C c. 500 0C d. 50.0

A

50. An inelastic collision occurs in one dimension, in which a 15kg block travelling at 5 m/s collides with a 10kg block travelling at 3 m/s in the same direction, and they stick together. What are the velocities of the blocks immediately after the collision? a. 4.2 m/s c. 5 m/s b. 3 m/s d. 2.55 m/s

A

6. In which situation is there work done on the system? a. a basket being lifted b. a man carrying a bag of content on his shoulder c. a boy pushing against the wall d. a weightlifter holding a barbell in the air

A

7. A car of mass 750 kg is being driven along a level road. This engine supplies a forward force of 3500 N and the total resistive force is 2000 N. What is the acceleration of the car? a. 2.0 m/s2 c. 4.5 m/s2 b. 3.5 m/s2 d. 7.0 m/s2

A

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A

An astronaut weighs 882 Newtons on Earth. The gravity of the moon is 1/6 of the Earth's gravity. Acceleration due to gravity on Earth is 9.8 m/s2 21. What would be the astronaut's weight on the moon? a. 147 N b. 90 N c. 980.6 N d. 697.8 N

A

An astronaut weighs 882 Newtons on Earth. The gravity of the moon is 1/6 of the Earth's gravity. Acceleration due to gravity on Earth is 9.8 m/s2 22. Why is the weight of an object on the moon only 1/6 of its weight on the earth? a. the moon has significantly less mass than the earth b. because the moon is far from the earth c. gravitational force on the moon is stronger than that of the earth d. the moon orbits the earth

A

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A D D D D

14. A capacitor acquires 0.003 Coulomb when 50 Volts is applied. Its capacitance is a. 0.6 microfarad c. 6.0 microfarad b. 60.0 microfarad d. 600.0 microfarad

B

15. If the external unbalanced force is zero, then a system I. At rest remains at rest II. In uniform motion moves in a straight line at constant speed III. Has no acceleration IV. Has an internal force that will cause it to accelerate a. I only c. I and II only b. I, II, and III only d. IV only

B

35. What kind of spherical mirror must be used, in order to give an inverted image 1/3 as large as an object placed 15 cm in front of it? a. Convex mirror c. Plane mirror b. Concave mirror d. Pocket mirror

B

38. A car moves in a clockwise direction in a circular track. It moves with a velocity of 10 m/s all throughout its course. Which of the following is true about the speed and velocity of the car? a. It has a changing speed and a constant velocity. b. It has a constant speed and a changing velocity. c. It has a constant speed and a constant velocity. d. Both the speed and the velocity are changing.

B

40. If both the net force and the mass are doubled, the acceleration will: a. Be doubled b. Remains the same c. Be reduced to ½ of its original value d. Be four times the original value

B

41. Which of the following is FALSE about the friction? a. Friction exists between materials that touch as they move past each other. b. If friction is absent, a moving object would need a force to keep it in motion. c. If friction is absent, an object moving horizontally would move forever. d. If friction is present, a force is needed to keep an object moving.

B

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B

An astronaut weighs 882 Newtons on Earth. The gravity of the moon is 1/6 of the Earth's gravity. Acceleration due to gravity on Earth is 9.8 m/s2 20. What is the astronaut's mass on earth? a. 147 kg b. 90 kg c. 980.6 kg d. 697.8 kg

B

39. Which of the following is FALSE for a projectile motion? a. The horizontal component for a projectile is completely independent of the vertical component of the motion. b. The vertical component for a projectile is completely independent of the horizontal component of motion. c. In a projectile motion, gravity both acts on the horizontal and vertical component of motion. d. The combined effects of the vertical and horizontal components produce a variety of curved paths that projectiles follow.

C

12. An orbiting satellite is moved from 10,000 to 20,000 km from the earth. This will result in what change in the gravitational attraction between the earth and the satellite? a. none- the attraction is the same b. one-half as much c. one-fourth as much d. twice as much

C

18. You tape two different soda straws together end-to-end to make a longer straw with no leaks. The two straws have radii of 8 millimeters and 10 millimeters, respectively. You drink a soda through your combination straw. In which straw is the speed of the liquid faster? a. Whichever one is nearest to your mouth b. The one of bigger radius c. The one of smaller radius d. Neither. The speed is the same in both straws.

C

2. A 1200-watt heater is used for raising the temperature of 1 L of water to boiling point. How long will it take for the water to boil if the initial temperature of water is 20˚C? (1 cal = 4.19 joules) a. 28 s b. 70 s c. 279 s d. 349 s

C

46. Light goes from medium A to medium B at an angle of incidence of 40 degrees. The angle refraction is 60 degrees. The speed of light in B: a. is less than in A b. is the same as that in A c. is greater than that in A d. may be any of the above, depending on the specific medium

C

49. A man weighing 800 Newtons climbs a flight of stairs 8 meters high. How much work does he do? a. 100 joules c. 6,400 joules b. 792 joules d. 606 joules

C

8. If the number of lines in a diffraction grating of a given width is decreased, which of the following will result? a. The wavelengths can be diffracted will be shorter b. The wavelengths that can be diffracted will be longer. c. The spectrum produced will be narrower. d. The spectrum produced will be broader

C

9. A 10-meter object is placed at a distance of 250 meters in front of a lens whose focal length is 125 meters. Which of the following describes the image formed? a. It is 4 meters long and inverted b. It is 4 meters long and erect. c. It is 10 meters long and inverted d. It is 10 meters long and erect.

C

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C

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C C

16. Which of the following will happen if a sample of gas is heated at constant pressure? a. The average kinetic energy of its molecules decreases, and the volume of the gas decreases. b. The average kinetic energy of its molecules increases, and the volume of the gas decreases. c. The average kinetic energy of its molecules decreases, and the volume of the gas increases. d. The average kinetic energy of its molecules increases, and the volume of the gas increases.

D

19. Which sample of water has the greatest vapour pressure? a. 50 mL at 30oC c. 150 mL at 15oC b. 100 mL at 120oC d. 75 mL at 40oC

D

1. The speed of sound in air at 200C is 344 m/s. What is the wavelength of the note produced by a piano key, if it has a frequency of 20Hz? a. 34.4 m b. 147.6 m c. 688 m d. 17.2 m

D

10. Which of the following statement is NOT true of protons and electrons? a. The positive charge in an atomic nucleus is due to the protons it contains b. All protons have the same charge c. Protons and electrons have charges equal in magnitude although opposite in sign d. Protons and electrons have equal masses

D

33. A 100 g copper initially at 950C is put inside an aluminium container with a piece of silver amounting to a mass of 200 grams and with water at 250C. Which of the following statement/s given must be TRUE? I. The final temperature of the system will be less than 950C. II. Copper loses heat while silver and water absorbs heat. III. The temperature of silver and water increases and the temperature of copper decreases. IV. The temperature of copper, silver, and water will eventually be equal. a. I and II only c. I, II, and III only b. I and III only d. I, II, III, and IV

D

36. A 5 cm object is placed 15 cm in front of a convex lens whose focal length is 12 cm. Which of the following describes the image formed? a. It is 20/9 cm long and inverted. b. It is 20/9 cm long and upright. c. It is 20 cm long and upright. d. It is 20 cm long and inverted.

D

4. Which of the following is true when the magnetic flux through a coil at 400 turns is reduced from 0.25 weber to 0 weber in 0.4 second? a. The emf is 250 volts. b. The induced emf in the coil is 220 volts. c. The emf is 220 volts. d. The induced emf in the coil is 250 volts.

D

45. Moving 3.5 × 10-6 coulomb of charge from point A to point B in an electric field requires 7.3 × 10-4 joule of work. The potential difference between points A and B is approximately... a. 1.6 x 10-9 V c. 1.0 x 10-14 V b. 4.2 x 10-3 V d. 2.1 x 102 V

D

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D