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AP Physics 1 Lesson 4 Homework Outcomes Quiz 4 Preparation

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Practice Problems I. A continuous force of 2.0 N is exerted on a 2.0 kg block to the right. The block moves with a constant horizontal velocity of 3.0 m/s to the right.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the magnitude and direction of the friction force exerted on the block. E. Determine the weight of the block. F. Determine the normal force exerted on the block. G. Determine the kinetic friction force on the surface.

II. A continuous force of 3.0 N is exerted on a 4.0 kg block to the right. The block moves with a constant horizontal velocity of 1.0 m/s to the right.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the magnitude and direction of the friction force exerted on the block. E. Determine the weight of the block. F. Determine the normal force exerted on the block. G. Determine the kinetic friction force on the surface.

III. A tension force of 3.0 N is exerted on a weight at an angle of 30° with respect to the horizontal, by the spring scale on the left, and the spring scale on the right.

A. Prepare a free-body diagram of all of the forces exerted on the weight. B. Prepare a free-body diagram of the net force exerted on the weight. C. Determine the net force exerted on the block.

IV. A tension force of 5.0 N is exerted on a weight at an angle of 45° with respect to the horizontal, by the spring scale on the left, and the spring scale on the right.

A. Prepare a free-body diagram of all of the forces exerted on the weight. B. Prepare a free-body diagram of the net force exerted on the weight. C. Determine the net force exerted on the block.

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D. Determine the horizontal component of the force Ft1 E. Determine the horizontal component of the force Ft2 F. Determine the net force exerted in the horizontal axis. G. Determine the vertical component of the force Ft1 H. Determine the vertical component of the force Ft2 I. Determine the sum of the tension forces in the vertical axis. J. Determine the weight of the block.

D. Determine the horizontal component of the force Ft1 E. Determine the horizontal component of the force Ft2 F. Determine the net force exerted in the horizontal axis. G. Determine the vertical component of the force Ft1 H. Determine the vertical component of the force Ft2 I. Determine the sum of the tension forces in the vertical axis. J. Determine the weight of the block.

V. A force of 5.0 N is exerted at an angle of 30° with respect to the horizontal on a 2.0 kg block to the right. The block moves with a horizontal velocity of 1.0 m/s to the right.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the component of the exerted force in the horizontal axis. E. Determine the magnitude and direction of the frictional force exerted on the block. F. Determine the weight of the block. G. Determine the component of the exerted force in the vertical axis. H. Determine the normal force exerted on the block. I. Determine the coefficient of friction on the surface.

VI. A force of 3.0 N is exerted at an angle of 45° with respect to the horizontal on a 1.5 kg block to the right. The block moves with a horizontal velocity of 2.0 m/s to the right.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the component of the exerted force in the horizontal axis. E. Determine the magnitude and direction of the frictional force exerted on the block. F. Determine the weight of the block. G. Determine the component of the exerted force in the vertical axis. H. Determine the normal force exerted on the block. I. Determine the coefficient of friction on the surface.

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VII. A continuous force of 1.5 N is exerted at an angle of 37° with respect to the horizontal on a 2.0 kg block to the right. The block moves with a constant horizontal velocity of 0.5 m/s to the right.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the component of the exerted force in the horizontal axis. E. Determine the magnitude and direction of the frictional force exerted on the block. F. Determine the weight of the block. G. Determine the component of the exerted force in the vertical axis. H. Determine the normal force exerted on the block. I. Determine the coefficient of friction on the surface.

VIII. A continuous force of 3.0 N is exerted at an angle of 53° with respect to the horizontal on a 0.7 kg block to the right. The block moves with a constant horizontal velocity of 0.3 m/s to the right.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the component of the exerted force in the horizontal axis. E. Determine the magnitude and direction of the frictional force exerted on the block. F. Determine the weight of the block. G. Determine the component of the exerted force in the vertical axis. H. Determine the normal force exerted on the block. I. Determine the coefficient of friction on the surface.

VII. A 3 kg block slides down a 30° incline at a uniform velocity of 1.2 m/s.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the weight of the block. E. Determine component of the weight exerted parallel to the inclined plane.

VIII. A 1.5 kg block slides down a 37° incline at a uniform velocity of 0.9 m/s.

A. Prepare a free-body diagram of all of the forces exerted on the block. B. Prepare a free-body diagram of the net force exerted on the block. C. Determine the net force exerted on the block. D. Determine the weight of the block. E. Determine component of the weight exerted parallel to the inclined plane.

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F. Determine the magnitude and direction of the friction force exerted on the block. G. Determine component of the weight exerted perpendicular to the inclined plane. H. Determine the normal force exerted on the block. I. Determine the coefficient of friction on the surface.

F. Determine the magnitude and direction of the friction force exerted on the block. G. Determine component of the weight exerted perpendicular to the inclined plane. H. Determine the normal force exerted on the block. I. Determine the coefficient of friction on the surface.

Answer

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Multiple Choice Question

1.

A box rests on the smooth bed of a truck that is moving at a constant velocity to the right.

If the truck were to suddenly stop, the box would probably... A) remain at rest in the back of the truck B) slide to the right C) slide to the left

2.

A lawnmower is pushed with a constant force F, as shown in the diagram below.

As angle θ between the lawnmower handle and the horizontal increases, the horizontal component of F A) decreases B) remains the same C) increases

3.

A table exerts a 2.0-newton force on a book lying on the table.

The force exerted by the book on the table is

A) 0 N B) 0.20 N C) 2.0 N D) 20. N

4.

The handle of a lawn roller is held at 45D from the horizontal. A force, F, of 28.0 newtons is applied to the handle as the roller is pushed across a level lawn, as shown in the diagram below.

What is the magnitude of the force moving the roller forward?

A) 19.8 N B) 7.00 N C) 39.0 N D) 14.0 N

5.

A block is at rest on an inclined plane as shown in the diagram below.

As angle θ is increased, the component of the block's weight parallel to the plane

A) increases B) decreases C) remains the same

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6.

The diagram below represents two concurrent forces acting on a point.

Which vector best represents their resultant?

7.

A force of 6.0 newtons north and a force of 8.0 newtons east act concurrently on an object.

The magnitude of the resultant of the two forces is

A) 14. N B) 2.0 N C) 1.3 N D) 10. N

8.

The diagram below shows a person exerting a 300.-newton force on the handle of a shovel that makes an angle of 60.0 with the horizontal ground.

The component of the 300.-newton force that acts perpendicular to the ground is approximately

A) 350. N B) 260. N C) 300. N D) 150. N

9.

A force of 100. newtons is applied to an object at an angle of 30D from the horizontal as shown in the diagram below.

What is the magnitude of the vertical component of this force?

A) 50.0 N B) 100. N C) 0 N D) 86.7 N

10.

A ball of mass m is suspended from two string! of unequal length as shown above.

The tensions T1 and T2 in the strings must satisfy which of the following relations?

(A) Tl = T2 (B) T1 > T2 (C) T1 < T2 (D) Tl + T2 = mg (E) T1-T2 = mg

AP

11.

A push broom of mass m is pushed across a rough horizontal floor by a force of magnitude T directed at angle θ as shown above. The coefficient of friction between the broom and the floor is µ.

The frictional force on the broom has magnitude (A) µ(mg + Tsinθ) (B) µ(mg-Tsinθ) (C) µ(mg+ Tcosθ) (D) µ(mg-Tcosθ) (E) µmg

AP

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12

A 2-kilogram block slides down a 30° incline as shown above at a constant speed. Which diagram best represents the

forces exerted on the block?

AP

13. A block of weight W is pulled along a horizontal surface at constant speed v by a force F, which acts at an angle of θ with the horizontal, as shown above. The normal force exerted on the block by the surface has magnitude

(A) W - F cosθ (B) W-Fsinθ (C) W (D) W + Fsinθ (E) W + Fcosθ AP

14.

An object of weight W is suspended from the center of a massless string as shown above.

The tension at any point in the string is (A) 2Wcosθ (B) ½Wcosθ (C) Wcosθ (D) W/(2cosθ) (E) W/cosθ

AP

15.

Use this diagram for questions 18-19.

A plane 5 meters in length is inclined at an angle of 37°, as shown above. A block of weight 20 newtons is placed at the top of the plane and allowed to slide down.

The mass of the block is most nearly (A) 1.0 kg (B) 1.2 kg (C) 1.6 kg (D) 2.0 kg (E) 2.5 kg

AP

16.

The magnitude of the normal force exerted on the block by the plane is most nearly

(A) 10 N (B) 12 N (C) 16 N (D) 20 N (E) 33 N AP

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Free Response

I. Two 10-kilogram boxes are connected by a massless string that passes over a massless frictionless pulley as shown above. The boxes remain at rest, with the one on the right hanging vertically and the one on the left 2.0 meters from the bottom of an inclined plane that makes an angle of 60° with the horizontal.

You may use g = 10 m/s2, sin 60° = 0.87, and cos 60° = 0.50. a. Draw a free body diagram labeling all of the forces exerted on block A (on the incline) b. Draw a free body diagram labeling the net force exerted on block A. c. What is the weight of the block A? d. What is the component of the weight of the block A that acts parallel to the plane of the incline? e. What is the weight of block B (FTension)? f. What is the difference between the component of the weight of block A acting parallel to the plane and the FTension? g. In order for the system to remain in equilibrium, what must be exerting the force described in f? h. What is the coefficient of friction on the incline?