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1) A 76

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1) A 76.0 kg sprinter starts a race with an acceleration of 2.0 m/s2. What is the net external force on him? N 2. A cleaner pushes a 4.6 kg laundry cart in such a way that the net external force on it is 57.3 N. Calculate the magnitude of its acceleration (in m/s2). m/s2 3. In the figure below, the net external force on the 30 kg mower is stated to be 50 N. Please, note that Fnet is the vector sum of force of the person and force of friction on the mover. If the force of friction opposing the motion is 10 N, what force F is the person exerting on the mower? (Enter the magnitude.) N Suppose the mower is moving at 1.5 m/s when the force F is removed. How far will the mower go before stopping? m 4. The rocket sled drawn in the figure below is decelerated at a rate of 194.0 m/s2 What force is necessary to produce this deceleration? Assume that the rockets are off. The mass of the system is 2093 kg. N 5. The rocket sled shown in the figure below accelerates at a rate of 30.0 m/s 2. Its passenger has a mass of 83.0 kg. (b) Calculate the direction and magnitude of the total force the seat exerts against his body. (Enter the direction in degrees counterclockwise from the +x-axis and the force in N.)direction degress counterclockwise form +x magnitude N 6. Tom works at a garden store during the summer. He lifts a bag of fertilizer with a force of 132 N, and it moves upward with an acceleration of 0.733 m/s2. (a) What is the mass of the fertilizer bag? kg (b) How much does the fertilizer bag weigh? 7. You are driving your car with a mass of 1381 kg. You suddenly see the red light and apply your brakes for 1.2 s. The car slows down from 15.0 m/s to 9.00 m/s. (a)During the time the brakes were applied, what was the average force exerted on your car? Magnitude of force : N Correct How far did the car move while braking? 8.Tom and Jerry are enjoying an afternoon at the ice rink. They playfully place their hands together and push against each other. Tom's mass is 2.60 kg and Jerry's mass is 0.031 kg. c)If Jerry's acceleration is 3.10 m/s2 in magnitude, what is the magnitude of Tom's acceleration? 9. In a hotel elevator a man with a mass of 80.0 kg stands on a bathroom scale that measures the weight in Newton. a)The elevator accelerates upward from rest at a rate of 1.18 m/s2 for 1.5 s. What does the scale read during this 1.5 s interval? b)The elevator continues upward at constant velocity for 8.50 s. What does the scale read now? c)While still moving upward, the elevator's speed decreases at a rate of 0.50 m/s2 for 3.00 s. What is the scale reading during this time? 10. A contestant in a winter games event pushes a 53.1-kg rock across a frozen lake with a force of 25 N at 30.0o below the horizontal as shown in Figure (a) below. You may assume that the surface is frictionless. . (a)What is the normal force (in N) exerted by the lake surface on the rock? (refer to figure (a)). (b)Instead of pushing on the rock, the contestant now pulls on it with a rope over his shoulder at the same angle above the horizontal as in part (a). See Figure (b) above. Now what is the normal force (in N) exerted by the lake surface on the rock? ? 11 A constant force of 20.0 N is exerted on the tooth in the following figure.The angle between the wire and the horizontal is 11.0o. a) Calculate the vertical tension of wire. b) Calculate the horizontal component of the tension of the wire. 12 A skier with a mass of 60.0 kg slides down a frictionless ski slope that makes an angle of 17.0o above the horizontal. Choose the direction of the acceleration of the skier to be positive. a)What net force (in N) is acting on the skier? (Indicate the direction with the sign of your answer.) b)What is the acceleration (in m/s2) experienced by the skier? (Indicate the direction with the sign of your answer.) The rocket sled shown in the figure below accelerates at a rate of 30.0 m/s2. Its passenger has a mass of 83.0 kg. (a) Calculate the magnitude of the horizontal force the seat exerts against his body. (Enter the force in N.) 2490 N Compare this with his weight by using the ratio below. F| |W 3.06 (b) Calculate the direction and magnitude of the total force the seat exerts against his body. (Enter the direction in degrees counterclockwise from the +X-axis and the force in N.) direction 2490 x degress counterclockwise form +x magnitude o XIN Question Help: Read Submit Question A constant force of 20.0 N is exerted on the tooth in the following figure. The angle between the wire and the horizontal is 11.0°. a) Calculate the vertical tension of wire. -10 b) Calculate the horizontal component of the tension of the wire. 51.44 Question Help: Read Submit Question