For Exercises 1 through 5:
a. Draw an interaction diagram.
b. Identify the "system" on your interaction diagram.
c. Draw a free-body diagram for each object in the system. Use dashed lines to connect members of an action/reaction pair.
1. A soccer ball and a bowling ball have a head-on collision at this instant. Rolling friction is negligible.
2. A weightlifter stands up at constant speed from a squatting position while holding a heavy barbell across his shoulders.
3. A steel cable with mass is lifting a girder. The girder is speeding up.
4. Block A in FIGURE EX7.4 is heavier than block B and is sliding down the incline. All surfaces have friction. The rope is massless, and the massless pulley turns on frictionless bearings. The rope and the pulley are among the interacting objects, but you'll have to decide if they're part of the system.
FIGURE EX7.4 and FIGURE EX7.5
5. Block A in FIGURE EX7.5 is sliding down the incline. The rope is massless, and the massless pulley turns on frictionless bearings, but the surface is not frictionless. The rope and the pulley are among the interacting objects, but you'll have to decide if they're part of the system.
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
- 5. A baseball is thrown upward from a height of 3 meters above Earth's surface with an initial velocity of 10m/s, and the only force acting on it is gravity. The ball has a mass of 0.15kg at Earth's surface. A. Find the velocity v(t) of the baseball at time t. B. What is its velocity after 2 seconds? C. The graph of the baseballarrow_forwardA 48.42kg hunter ropes a 167.82 kg sleeping polar bear and pulls the bear towards him until they meet. Originally they are 211.22 m apart on frictionless ice. When the hunter pulls the polar bear to him the hunter will move... a. 52 b. 810 c. 67 d. 160arrow_forwardYou push a 40.0 kg box across a floor at a constant velocity of 1.00 m/s. the coefficient of kinetic friction is ?k = 0.15. a. Draw a free body diagram. b. Decide of which type of problem-solving technique you need, inertial or dynamic. c. Determine the value of your push in newtonsarrow_forward
- 3. You push a grocery cart along a level floor in the presence of friction effects between the cart and the floor. a. Draw force diagrams for you, the cart, and the floor/earth. Fully label all vectors. b. While you are making the cart speed up, how does the size of the force you apply on the cart b. compare to the size of the force the cart exerts on you? Explain. c. While you are making the cart speed up, how does the size of the frictional force on the cart by the floor compare to the frictional force on you by the floor?arrow_forwardA 20.0 kg block is projected up an inclined slope by a force of 1250N acting on the block over a distance of 25cm. The block comes to a standstill as it reaches the top. The slope is inclined at 15° and the coefficient of kinetic friction between the block and the slope is 0.400. Draw a before-and-after pictorial representation (before being released and at rest at top of a. slope). b. Draw a free body diagram of the block on the incline (not in contact with spring). Insert the displacement vector of the block onto your free body diagram. c. Draw an energy bar chart representing the energy states of the system at the initial and final positions. d. Solve for the distance the block moves up the slope.arrow_forwardA light block of mass m and a heavy block of mass M are attached to the ends of a rope. A student holds the heavier block and lets the lighterblock hang below it, as shown. Then she lets go. Air resistance can be neglected.a. What is the tension in the rope while the blocks are falling, before either hits the ground?b. Would your answer be different if she had been holding the lighter block initially?arrow_forward
- A 1300 kg car A struck a parked car B with mass 1200kg. the wheels of car B jams a break and known to slide 2m after the impact. If the coefficient of kinetic friction between car B and the road is 0.80 and the coefficient of restitution is 0.40. a. What is the velocity of B after impact? b. What is the velocity of A before impact? c. How long does Car slides after impact before it stops? 'arrow_forwardThree boxes in contact slide side-by-side on a smooth, friction-less, horizontal floor. Their masses are 5.0-kg, 3.0-kg, and 2.0-kg, with the 3.0-kg box in the center. A force of 50 N pushes on the 5.0-kg box, which pushes against the other two boxes. A. Draw the free-body diagrams for each of the boxes. B. What magnitude force does the 3.0-kg box exert on the 5.0-kg box? C. What magnitude force does the 3.0-kg box exert on the 2.0-kg box?arrow_forwardA book sits on a table. You press downwards on the book. The book does not move. Answer the following questions about the situation. a. Draw a force diagram for the book. Attach this diagram to #8 as a document or picture. If you can't attach a diagram, list the direction of each force on the book and the object causing it. b. Is one of those forces bigger than the others? If so, explain why. If not, explain why not. c. For EACH force you listed in a), write down the partner force to that force. Make sure to also include which way each partner forc points.arrow_forward
- A stuntman drives a car of mass 1125 kg east with a speed of 20 m/s. a. If the car accelerates at a rate of –2 m/s 2 , how long will it take the car to go 50 m? b. The stuntman drives the car off an 80 m cliff while going 15 m/s. How long will it take the car to land? c. How far horizontally from the cliff will the car land?arrow_forward4. A 35 kg child pulls a 12 kg wagon up a hill at 0.6 m/s. The wagon exerts 60 N of force on the child. Draw a quantitative force diagram for the wagon. a. 30 b. Explain how you applied Newton's first law to make the force diagram quantitative. c. Explain how you applied Newton's third law to make the force diagram quantitative.arrow_forward2. A 1,480-N crate is being pushed across a level floor at a constant speed by a force F of 370 N at an angle of 20.0° below the horizontal, as shown in the figure a below. The floor has some amount of friction. 20.0° a a. Draw a free body diagram of all the forces on the crate. b. Write out one equation for the y component of the resultant force. Hint: The crate does not move in the y direction. Write out one equation for the x component of the resultant force. Hint: the crate moves in the x direction. C. d. Determine the Normal force. e. What is the coefficient of kinetic friction between the crate and the floor? (Enter vour answer to at least three decimal places.)arrow_forward
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University