27. [-/2 Points] DETAILS OSCOLPHYS2016 7.2.WA.014.TUTORIAL. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER As shown in the figure below, two masses m, = 5.00 kg and m, which has a mass 80.0% that of my, are attached to a cord of negligible mass which passes over a frictionless pulley also of negligible mass. If m, and m, start from rest, after they have each traveled a distance h = 1.00 m, use energy content to determine the following. 1/2 (a) the speed (in m/s) v of the masses m/s (b) the magnitude (in N) of the tension 7 in the cord N Additional Materials Reading28. [-/4 Points] DETAILS OSCOLPHYS2016 7.2.WA.020. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHE A warehouse worker is pushing a 90.0 kg crate with a horizontal force of 288 N at a speed of v = 0.870 m/s across the warehouse floor. He encounters a rough horizontal section of the floor that is 0.75 m long and where the coefficient of kinetic friction between the crate and floor is 0.357. V (a) Determine the magnitude and direction of the net force acting on the crate while it is pushed over the rough section of the floor. magnitude N direction ---Select--- (b) Determine the net work done on the crate while it is pushed over the rough section of the floor. (c) Find the speed of the crate when it reaches the end of the rough surface. m/s29. [-/4 Points] DETAILS OSCOLPHYS2016 7.1.WA.005. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A physics TA pushes a 20.0 kg equipment cart at a constant velocity for a distance of 20.0 m down the hall. The force she exerts on the cart is directed at an angle 21.0 below the horizontal, and the force of friction opposing the motion of the cart is 42.0 N. Determine the following. (a) the magnitude (in N) of the force exerted on the cart by the TA N (b) the work done (in ]) by the force the TA exerts on the cart (c) the work done (in ]) by the force of friction acting on the cart (d) the work done (in ]) by the force of gravity acting on the cart Additional Materials Reading 30. [-/3 Points] DETAILS OSCOLPHYS2016 8.1.P.001. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER (a) Calculate the momentum of a 1850 kg elephant charging a hunter at a speed of 7.50 m/s. kg . m/s (b) Compare the elephant's momentum with that of a 0.0400 kg bullet fired at a speed of 600 m/s. elephant's momentum bullet's momentum (c) What is the momentum in kilograms times meters per second of the 90.0 kg hunter running at 7.00 m/s after missing the elephant? kg . m/s31. [-13 Points] DETAILS OSCOLPHY52016 8.1.WA.002. NOTES ASK YOUR TEACHER PRACTICE ANOTHER Two carts mounted on an air track are moving toward one another. Cart 1 has a speed of 0.8 m/s and a mass of 0.42 kg. Cart 2 has a mass of 0.6? kg. (a) If the total momentum of the system is to be zero, what is the initial speed of Cart 2 in meters per second? E W. (b) Does it follow that the kinetic energy of the system is also zero since the momentum of the system is zero? -:III:- Yes '31} No (c) Determine the system's kinetic energy in joules in order to substantiate your answer to part (b). E J Additional Materials I-:I Reading 32. [-1'2 Points] DETAILS OSCOLPHY52016 8.2.P.013. NOTES ASK YOUR TEACHER PRACTICE ANOTHER A 89.0 kg person is riding in a car moving at 23.0 mfs when the car runs into a bridge abutment. (Assume the initial velocity is in the positive direction.) (a) Calculate the average force (in N) on the person if he is stopped by a padded dashboard that compresses an average of 1.00 cm. (Indicate the direction with the sign of your answer.) :qu (b) Calculate the average force (in N) on the person if he is stopped by an air bag that compresses an average of 15.0 cm. [Indicate the direction with the sign of your answer.) :qu 33. [-/3 Points] DETAILS OSCOLPHYS2016 8.2.WA.009. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A particle with a mass of 1.50 kg is acted on by a force F, acting in the x-direction. If the magnitude of the force varies in time as shown in the figure below, determine the following. Fx (N) 8 6 4 2 t (S) 1 2 3 4 5 (a) impulse of the force (in kg . m/s ) kg . m/s (b) final velocity of the particle (in m/s) if it is initially at rest m/s (c) Find the final velocity of the particle (in m/s) if it is initially moving along the x-axis with a velocity of -1.80 m/s. m/s34. [-/2 Points] DETAILS OSCOLPHYS2016 8.3.WA.020. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A car with a mass of 980 kg is initially traveling east toward an intersection with a speed of v = 21.9 m/s and a 1500 kg pickup is traveling north toward the same intersection. The car and truck collide at the intersection and stick together. After the collision, the wreckage (car and truck) moves off in a direction of 39.00 above the x-axis. Determine the initial speed of the truck and the final speed of the wreckage in meters per second. initial speed of the truck m/s final speed of the wreckage m/s35. [-/2 Points] DETAILS OSCOLPHYS2016 8.2.P.018. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A 0.500 kg hammer is moving horizontally at 4.50 m/s when it strikes a nail and comes to rest after driving it 1.00 cm into a board. (a) Calculate the duration of the impact in seconds. S (b) What was the average force in newtons exerted on the nail? N + Additic24. [-/1 Points] DETAILS OSCOLPHYS2016 7.1.P.005. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Calculate the work done (in ]) by an 80.0 kg man who pushes a crate 4.05 m up along a ramp that makes an angle of 20.0 with the horizontal. (See the figure below.) He exerts a force of 490 N on the crate parallel to the ramp and moves at a constant speed. Be certain to include the work he does on the crate and on his body to get up the ramp. F Additional Materials Reading25. [-/1 Points] DETAILS OSCOLPHYS2016 7.1.P.006. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER How much work is done by the boy pulling his sister 36 m in a wagon as shown in the figure below? F 30 d O Assume no friction acts on the wagon. (Assume d = 36 m and F = 56 N.) Additional Materials Reading26. [-/5 Points] DETAILS OSCOLPHYS2016 7.1.P.007. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A shopper pushes a grocery cart 25.0 m at constant speed on level ground, against a 32.0 N frictional force. He pushes in a direction 28.50 below the horizontal. (a) What is the work (in ]) done on the cart by friction? (b) What is the work (in ]) done on the cart by the gravitational force? (c) What is the work (in ]) done on the cart by the shopper? (d) Find the force the shopper exerts (in N), using energy considerations. (Enter the magnitude.) N (e) What is the total work (in ]) done on the cart? + Additional Materials Reading