Which of the following correctly displays the four fundamental forces in terms of decreasing magnitude?   1. Electromagnetic force, strong nuclear force, gravity, weak nuclear force 2. Gravity, electromagnetic force, strong nuclear force, weak nuclear force 3. Strong nuclear force, electromagnetic force, weak nuclear force, gravity 4. Gravity, electromagnetic force, weak nuclear force, strong nuclear force

6. An apparatus like the one Cavendish used to find G has a large lead ball that is 5.9 kg in mass and a small one that Is 0.047 kg. Their centers are separated by 0.055 m. Find the force of attraction between them.

46. If a constant, nonzero force is applied to an object, what can you say about the velocity and acceleration of the object? A. Velocity is constant; acceleration varies B. Velocity varies; acceleration constant C. Velocity is constant; acceleration constant D. Velocity varies; acceleration varies 47. Static friction VARIES from zero to its maximum value. A. True B. False   48. The normal force is ALWAYS ___ to the surface. A. Parallel B. Perpendicular C. Neither

60. An 8.0-kilogram block and a 2.0-kilogram block rest on a horizontal frictionless surface. When horizontal force F is applied to the 8.0-kilogram block, it accelerates at 5.0 meters per second east. If the same force was applied to the 2.0-kilogram block, the magnitude of the block's acceleration would be (1) 1.3 m/s2 (2) 2.5 m/s2 (3) 10. m/s2 (4) 20. m/s SHOW WORK, CIRCLE ANSWER, WRITE NEAT

18. According to Newton's third law, every force is accompanied by an equal and opposite reaction force. The reason that these forces do not cancel each other is a. the action force acts for a longer time period b. the two forces are not always in the same direction c. one of the two forces is greater than the other d. the two forces act upon different objects; only forces on the same object can balance each other. e. . nonsense! They do cancel each other. Objects accelerate because of the presence of a third force Justify your answer:

2. Give three examples that demonstrate Newton's third law of motion. Explain how each example demonstrates the law.

1- Calculate the magnitude of the force that gravity exerts on each of the following objects. a) A car of mass 1250 kg. b) A table tennis ball of mass 4 grams. c) A lorry of mass 4.2 tones. 2- The weight of a body is 441 N. Calculate the mass of the body. 3- A slide-loving pig slides down a certain 35° slide in twice the time it would take to slide down a frictionless 35° slide. What is the coefficient of kinetic friction between the pig and the slide?

Directions: Identify what law of motion is being shown in the following situations. 1. When an astronaut is drifting in space, he will travel at a constant speed in a straight line forever if no force act on it. 2. Lighter vehicles accelerate faster than heavier vehicles. 3. When we walk on the ground, our foot pushes the ground backward, and as a reaction, the ground pushes our foot forward. 4. When you push a cart, the cart pushes back against you. 5. Men in space find it more difficult to stop moving because of lack of gravity acting against them. 6. Pulling a table cloth out under plates. 7. Two opposing team playing tug of war. 8. Firing a gun. 9. Hammering a nail. 10. When you are driving a car, and you hit the break and your body moved forward.