AP Physics Quiz Chap 3, 4



1) (AP Test FRQ 2003M1) The 100 kg box shown above is being pulled along the x-axis by a student. The box slides across a rough surface, and its position x varies with time t according to the equation

[pic],

where x is in meters and t is in seconds.

a. Determine the speed of the box at time t = 0.

b. Determine the following as functions of time t.

i. The kinetic energy of the box

ii. The net force acting on the box

iii. The power being delivered to the box

c. Calculate the net work done on the box in the interval t = 0 to t = 2s.

d. Indicate below whether the work done on the box by the student in the interval t=0 to t=2s would be greater than, less than, or equal to the answer in part (c).

_____Greater than

_____Less than

_____Equal to

Justify your answer

2) (AP Test FRQ 2004M1) A rope of length L is attached to a support at point C. A person of mass m1 sits on a ledge at position A holding the other end of the rope so that it is horizontal and taut, as shown above. The person then drops off the ledge and swings down on the rope toward position B on a lower ledge where an object of mass m2 is at rest. At position B the person grabs hold of the object and simultaneously lets go of the rope. The person and object then land together in the lake at point D, which is a vertical distance L below position B. Air resistance and the mass of the rope are negligible. Derive expressions for each of the following in terms of m1, m2, L, and g.

a. The speed of the person just before the collision with the object

b. The tension in the rope just before the collision with the object

c. The speed of the person and object just after the collision

d. The ratio of the kinetic energy of the person-object system before the collision to the kinetic energy after the collision

e. The total horizontal displacement x of the person from position A until the person and object land in the water at point D.

3) (AP Test FRQ 2002M1) A crash test car of mass 1,000 kg moving at constant speed of 12 m/s collides completely inelastically with an object of mass M at time t = 0. The object was initially at rest. The speed v in m/s of the car-object system after the collision is given as a function of time t in seconds by the expression

[pic]

a. Calculate the mass M of the object.

b. Assuming an initial position of x = 0, determine an expression for the position of the car-object system after the collision as a function of time t.

c. Determine an expression for the resisting force on the car-object system after the collision as a function of time t.

d. Determine the impulse delivered to the car-object system from t = 0 to t = 2.0 s.

4) (AP Test FRQ 1998M3) Block 1 of mass m1 is placed on block 2 of mass m2 which is then placed on a table. A string connecting block 2 to a hanging mass M passes over a pulley attached to one end of the table, as shown above. The mass and friction of the pulley are negligible. The coefficients of friction between blocks 1 and 2 and between block 2 and the tabletop are nonzero and are given in the following table.

[pic]

Express your answers in terms of the masses, coefficients of friction, and g, the acceleration due to gravity.

a. Suppose that the value of M is small enough that the blocks remain at rest when released. For each of the following forces, determine the magnitude of the force and draw a vector on the block provided to indicate the direction of the force if it is nonzero.

i. On block 1 draw the normal force N1 exerted on block 1 by block 2

ii. On block 1 draw the friction force f1 exerted on block 1 by block 2

iii. On block 2 draw the force T exerted on block 2 by the string

iv. On block 2 draw the normal force N2 exerted on block 2 by the tabletop

v. On block 2 draw the friction force f2 exerted on block 2 by the tabletop

b. Determine the largest value of M for which the blocks can remain at rest.

(This question is continued on the next page)

c. Now suppose that M is large enough that the hanging block descends when the blocks are released. Assume that blocks 1 and 2 are moving as a unit (no slippage). Determine the magnitude a of their acceleration.

d. Now suppose that M is large enough that as the hanging block descends, block 1 is slipping on block 2. Determine each of the following.

i. The magnitude a1 of the acceleration of block 1

ii. The magnitude a2 of the acceleration of block 2

-----------------------

[pic]

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download