Physics Final
42) A small cart of mass m is initially at rest. It collides elastically with a large cart of mass 4m and velocity, v. The large cart loses half of it's kinetic energy to the little cart. The little cart now has a velocity of
1.41 v
32) Two travelling waves of equal frequency, one of amplitude 4 cm and the other of amplitude 6 cm, superimpose in a single medium. Which of the following best describes the displacement, D, of the resultant wave?
2 cm < D < 10 cm
17) A standing wave is sent through a pipe with one open end and it has a fundamental frequency of 4 Hz. Which of the following could be a harmonic frequency?
36 Hz
3) What happens to the force of gravitational attraction between two small objects if the mass of each object is doubled and the distance between their centers is doubled?
It remains the same.
22) An ideal battery of constant voltage, V, supplies current to a circuit that has a total resistance, R. If R is doubled, what will happen to the total power, P, dissipated by the circuit?
It will be halved
15) If the force of gravity between the moon and the Earth were to stop, which statement best describes the resulting motion of the moon?
It would continue rotating but stop revolving around the Earth.
26) If L, M and T denote the dimensions of Length, Mass and Time, respectively, what are the dimensions of power?
ML^2/T^3
18) Three light bulbs, each with a resistance of R, are connected in parallel to a battery in a simple circuit. If the middle bulb goes out
the bulbs will stay on and the current will decrease
23) Two spheres, +5e and -6e, come into contact to produce a net charge. Which of the following is/are a possible combination of spheres producing the same net charge?
+3e and -4e
35) In the graph below, the instantaneous velocity at 9 seconds is closest to:
- 11/4 m/s
44) What is the power developed by the force in the previous problem?( P = Flld/t)
0
6) If the coefficient of friction, u, between the block and the incline is 0.4, how much work is done by the normal force on the block as it slides down the full length of the incline?
0 jewels
10) If the pulley system is frictionless, what will be the acceleration of the blocks once they are released from rest?
0.7g
39) A projectile of mass, m, is fired into the air at some angle θ. If its launch velocity is Vo, which of the following expressions represents the object's kinetic energy at the peak of its motion?
1/2 m(Vocosθ)^2
5) If the surface of the incline is frictionless, with what speed will the block reach the bottom if it was released from rest at the top?
10 m/s
16) An object of mass 5 kg is acted upon by exactly four forces, each of magnitude 10N. Which of the following could NOT be the resulting acceleration of the object?
10 m/s^2
4) If the surface of the incline is frictionless, how long will it take the block to reach the bottom if it was released from rest at the top?
2.0 s
38) A tube with one end closed resonates for a wave with wavelength λa . The next shorter wavelength at which resonance will occur is λb. The ratio of λa / λb is
5/3
1) A 25 kg cart is accelerated from rest to a velocity of 3.5 m/s over an interval of 1.5 s. Find the net force applied to the cart.
58.33 N
52) The electric field strength in a vacuum at a point at a distance from a source charge is NOT dependent on which of the following?
Another charge placed at that point. The sign of the source charge.
19) In a plane diagram (see next slide), four point charges are arranged at the corners of a square with Point B at the center. A positive charge would experience no net force at Point ____.
B only
14) The graphs above show the changes in speed for two different blocks. While speeding up both blocks had to overcome friction, f. Which of the two blocks had more power provided to it?
Block 1
24) In which of the following situations involving a source of sound and a detector of the sound is it possible that there is NO perceived Doppler shift?
Both source and detector travel in same direction.
21) If the rod in the figure below is uniform and has a mass, m, what is the tension in the supporting string? The rod is free to rotate about point P.
Ft = ½ mg
13) A horizontal spring-block oscillator is in motion when a second block of equal mass falls on top of the oscillating block. If the two blocks stick together, what effect will this have on the amplitude of the oscillations?
Depends on when in the cycle the mass is dropped
36) Two charges are placed as shown at the vertices of an equilateral triangle. What is the direction of the electric field at point P?
Direction D
2) A cart with a mass m is accelerated from rest to velocity v over time interval t. Derive an expression for the net force applied to the cart in terms of m, v and t.
F=mv/t
47) Which of the following changes to a circuit will always bring about an increase in the current?
Increased voltage and decreased resistance
9) Sound waves travel at 350 m/s through warm air and at 3,500 m/s through brass. What happens to the wavelength of a 700 Hz acoustic wave as it enters brass from warm air?
It increases by a factor of 10
51) A pendulum undergoes simple harmonic motion. There is no friction present for the mass on the string. Which of the following statements are true?
Mechanical energy is constant. The period of the mass is constant.
8) The graph below shows a wave. What quantity of the wave does the indicated segment represent?
Period
37) If a charge +q is placed at point P, the electric field at point P would (refer to the previous problem)
Remain the same
48) If the acceleration of an object is not zero, then which of the following could be constant? Select two answers.
Speed and Kinetic Energy
20) A beam of monochromatic light entering a glass window pane from the air will experience a change in
Speed and wavelength
49) A lightweight toy car crashes head on into a heavier toy truck. Which of the following statements is true as a result of the collision? (Select two
The acceleration experienced by the car is greater than the acceleration experienced by the truck. The total momentum in the collision will be conserved.
11) Two people, one of mass 100 kg and the other of mass 50 kg, stand facing each other on an ice-covered (frictionless) pond. If the heavier peron pushes the lighter one with a force F, then
The acceleration of the lighter person will be twice the acceleration of the heavier person.
45) Two objects, A & B, have equal charge and equal mass. They are not in motion because the gravitational and electrostatic forces between them are equal. If the mass of Object A is halved, equilibrium will be maintained if...
The charge on B was halved
50) A musician plucks a string on an acoustic guitar. Standing waves will most likely occur in which of the following media?
The guitar string. The air inside the guitar.
34) A uniform bar is lying on a flat table. Besides the gravitational and normal forces (which cancel), the bar is acted upon by two other forces, F1 and F2, which are parallel to the surface of the table. If the net force on the rod is zero, then which one of the following is true?
The net torque will be zero if F1 and F2 are applied at the same point.
28) When turning a corner on a bicycle, the rider leans into the turn. The frame of the bike is nearly parallel to which vector?
The sum of the normal and frictional forces.
29) A simple pendulum executes simple harmonic motion as it swings through small angles of oscillation. If θmax denotes the amplitude of the oscillations, which of the following statements is true?
When θ = 0, the tangential acceleration is 0.
40) A man stands in an elevator as it begins to ascend. Does the normal force from the floor do work on the man?
Yes, and the work done is positive.
25) A projectile is launched with an initial velocity of magnitude, a, at an angle, β, to the horizontal. Find its maximum vertical displacement, ignoring effects due to air.
a^2sin^2β/2g
30) In the diagram, a positive charge and a negative charge are placed at y = -2 and y = 3, respectively. If the negative charge has a greater magnitude, then the only place of 0 net electric field would be
along the negative y-axis
41) An alarm whose frequency is 400 Hz is dropped out of a third floor window. The student who drops it measures the frequency with a very sensitive oscilloscope. The measured frequency
appears lower than 400 Hz and f decreases as it falls
46) Which configuration of batteries and resistors will create the greatest current?
high voltage battery with resistors in parallel
31) A wire is split into 4 segments and they have resistances of R, 2R, 1/2R, and 4R in that order. Which of the following sets of changes from one segment to the next could correctly account for the changes in resistance?
length is doubled area is halved radius is doubled
33) An elevator is rising. In order to determine the tension in the cables pulling it, which values for the elevator would you need to know?
mass and acceleration
7) Two satellites are in circular orbit around the Earth. The distance from Satellite 1 to Earth's center is r1, and the distance from Satellite 2 to the Earth's center is r2. What is the speed of Satellite 2?
v2 = v1(r1/r2)^½
