AP Physics Review Created by Educational Technology Network. www.edtechnetwork.com 2009

Kinematics Vectors / Proj Forces Work / NRG Random 10 10 10 10 10 20 20 20 20 20 30 30 30 30 30 40 40 40 40 40 50 50 50 50 50

Topic 1 – 10 Points QUESTION: ANSWER: C The position of a particle moving along the x axis is given by , where t is in s. What is the average velocity during the time interval t = 1.0 s to s? a. –6.0 m/s b. –4.0 m/s c. –2.0 m/s d. –8.0 m/s e. 8.0 m/s ANSWER: C

Topic 1 – 20 Points QUESTION: ANSWER: D Vx is the velocity of a particle moving along the x axis as shown. If x = 2.0 m at t = 1.0 s, what is the position of the particle at t = 6.0 s? a. –2.0 m b. +2.0 m c. +1.0 m d. –1.0 m e. 6.0 m ANSWER: D D

Topic 1 – 30 Points QUESTION: ANSWER: D A rocket, initially at rest, is fired vertically with an upward acceleration of 10 m/s2. At an altitude of 0.50 km, the engine of the rocket cuts off. What is the maximum altitude it achieves? a. 1.9 km b. 1.3 km c. 1.6 km d. 1.0 km e. 2.1 km ANSWER: D

Topic 1 – 40 Points QUESTION: ANSWER: A A ball is thrown vertically upward with an initial speed of 20 m/s. Two seconds later, a stone is thrown vertically (from the same initial height as the ball) with an initial speed of 24 m/s. At what height above the release point will the ball and stone pass each other? a. 17 m b. 21 m c. 18 m d. 27 m e. 31 m ANSWER: A

Topic 1 – 50 Points QUESTION: ANSWER: The position of an object at equal time intervals is shown below: which graph below correctly represents position versus time for this object? ANSWER: E

Topic 2 – 10 Points QUESTION: ANSWER: A The initial speed of a cannon ball is 0.20 km/s. If the ball is to strike a target that is at a horizontal distance of 3.0 km from the cannon, what is the minimum time of flight for the ball? a. 16 s b. 21 s c. 24 s d. 14 s e. 19 s ANSWER: A

Topic 2 – 20 Points QUESTION: ANSWER: C A particle moves at a constant speed in a circular path with a radius of 2.06 cm. If the particle makes four revolutions each second, what is the magnitude of its acceleration? a. 20 m/s2 b. 18 m/s2 c. 13 m/s2 d. 15 m/s2 e. 24 m/s2 ANSWER: C

Topic 2 – 30 Points QUESTION: ANSWER: C A 0.14-km wide river flows with a uniform speed of 4.0 m/s toward the east. It takes 20 s for a boat to cross the river to a point directly north of its departure point on the south bank. What is the speed of the boat relative to the water? a. 5.7 m/s b. 8.5 m/s c. 8.1 m/s d. 7.0 m/s e. 6.4 m/s ANSWER: C

Topic 2 – 40 Points QUESTION: ANSWER: C Two balls, projected at different times so they don’t collide, have trajectories A and B, as shown below. Which statement is correct? a. must be greater than . b. Ball A is in the air for a longer time than ball B. c. Ball B is in the air for a longer time than ball A. d. Ball B has a greater acceleration than ball A. e. Ball A has a greater acceleration than ball B. ANSWER: C

Topic 2 – 50 Points QUESTION: ANSWER: D A projectile starts at the coordinate origin, where the displacement vector also originates. The initial velocity, , makes an angle q0 with the horizontal where . At the instant when the projectile is at the highest point of its trajectory, the displacement, velocity and acceleration vectors are , and . Which statement is true? a. r is parallel to v. b. r is perpendicular to v. c. v is parallel to a. d. v is perpendicular to a. e. r is perpendicular to a. ANSWER: D

Topic 3 – 10 Points QUESTION: ANSWER: D An object of unknown weight is suspended as shown. The tension in rope 1 is 25 lb, and the tension in rope 2 is 31 lb. What is the weight of the suspended object? a. 36 lb b. 33 lb c. 41 lb d. 39 lb e. 56 lb ANSWER: D

Topic 3 – 20 Points QUESTION: ANSWER: B The tension in a string from which a 4.0-kg object is suspended in an elevator is equal to 44 N. What is the acceleration of the elevator? a. 11 m/s2 upward b. 1.2 m/s2 upward c. 1.2 m/s2 downward d. 10 m/s2 upward e. 2.4 m/s2 downward ANSWER: B

Topic 3 – 30 Points QUESTION: ANSWER: A A 4.0-kg block slides down a 35 incline at a constant speed when a 16-N force is applied acting up and parallel to the incline. What is the coefficient of kinetic friction between the block and the surface of the incline? a. 0.20 b. 0.23 c. 0.26 d. 0.33 e. 0.41 ANSWER: A

Topic 3 – 40 Points QUESTION: ANSWER: B The horizontal surface on which the objects slide is frictionless. If M = 2.0 kg, the tension in string 1 is 12 N. Determine F. a. 25 N b. 20 N c. 30 N d. 35 N e. 40 N ANSWER: B

Topic 3 – 50 Points QUESTION: ANSWER: B If F = 40 N and M = 1.5 kg, what is the tension in the string connecting M and 2M? Assume that all surfaces are frictionless. a. 13 N b. 23 N c. 36 N d. 15 N e. 28 N ANSWER: B

Topic 4 – 10 Points QUESTION: ANSWER: D A 2.5-kg object falls vertically downward in a viscous medium at a constant speed of 2.5 m/s. How much work is done by the force the viscous medium exerts on the object as it falls 80 cm? a. +2.0 J b. +20 J c. –2.0 J d. –20 J e. +40 J ANSWER: D

Topic 4 – 20 Points QUESTION: ANSWER: A A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.5 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B? a. 2.7 J b. 1.0 J c. 2.2 J d. 1.6 J e. 3.2 J ANSWER: A

Topic 4 – 30 Points QUESTION: ANSWER: B A 10-kg block on a rough horizontal surface is attached to a light spring (force constant = 1.4 kN/m). The block is pulled 8.0 cm to the right from its equilibrium position and released from rest. The frictional force between the block and surface has a magnitude of 30 N. What is the kinetic energy of the block as it passes through its equilibrium position? a. 4.5 J b. 2.1 J c. 6.9 J d. 6.6 J e. 4.9 J ANSWER: B

Topic 4 – 40 Points QUESTION: ANSWER: D When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction , then dragged back along the same path to its original position, the work done by friction is ANSWER: D

Topic 4 – 50 Points QUESTION: ANSWER: B A skier weighing 0.70 kN goes over a frictionless circular hill as shown. If the skier’s speed at point A is 9.2 m/s, what is his speed at the top of the hill (point B)? a. 3.1 m/s b. 6.2 m/s c. 5.2 m/s d. 4.1 m/s e. 6.5 m/s ANSWER: B

Topic 5 – 10 Points QUESTION: ANSWER: A 10-kg block on a horizontal frictionless surface is attached to a light spring (force constant = 0.80 kN/m). The block is initially at rest at its equilibrium position when a force (magnitude P = 80 N) acting parallel to the surface is applied to the block, as shown. What is the speed of the block when it is 13 cm from its equilibrium position? a. 0.85 m/s b. 0.89 m/s c. 0.77 m/s d. 0.64 m/s e. 0.52 m/s ANSWER: A

Topic 5 – 20 Points QUESTION: ANSWER: C When Jim and Rob ride bicycles, Jim can only accelerate at three quarters the acceleration of Rob. Both start from rest at the bottom of a long straight road with constant upward slope. If Rob takes 5.0 minutes to reach the top, how much earlier should Jim start to reach the top at the same time as Rob? a. 25 s b. 40 s c. 46 s d. 55 s e. 75 s ANSWER: C

Topic 5 – 30 Points QUESTION: ANSWER: When is the world going to end according to the Mayan Calendar? A. Dec 18 (ahh..) B. Dec 21 (we’ve still got some time left!) C. Jan 1 D. Feb 31 ANSWER: B

Topic 5 – 40 Points QUESTION: ANSWER: D A car enters a level, unbanked semi-circular hairpin turn of 300 m radius at a speed of 40 m/s. The coefficient of friction between the tires and the road is . If the car maintains a constant speed of 40 m/s, it will a. attempt to dig into the road surface. b. tend to veer toward the center of the semicircle. c. arrive safely at the end of the semicircle. d. tend to veer toward the outside of the circle. e. veer toward the center for the first quarter-circle, then veer toward the outside for the second quarter-circle. ANSWER: D

Topic 5 – 50 Points QUESTION: ANSWER: D The site from which an airplane takes off is the origin. The x-axis points east; the y-axis points straight up. The position and velocity vectors of the plane at a later time are given by The plane is most likely a. just touching down. b. in level flight in the air. c. ascending. d. descending. e. taking off. ANSWER: D