Physics 141
Calories of the food type are equal to which of the following?
4 186 J
Which is not an example of approximate simple harmonic motion?
A ball bouncing on the floor.
A vector lying in the xy plane has components of opposite sign. The vector must lie in which quadrant?
Either the second or fourth quadrant
An ice cube with a small solid steel sphere frozen inside floats in a glass of water filled to the brim. What happens to the level of water in the glass as a result of the ice melting?
It goes down.
A mass-spring system on a horizontal frictionless surface is set in simple harmonic motion with amplitude A. The mass is then doubled and the system is again set into simple harmonic motion with the same amplitude. Which of the following is true about the total mechanical energy of the system due to doubling the mass?
It has not changed
Suppose there is an object for which F = +kx. What will happen if the object is moved away from equilibrium (x = 0) and released?
It will move further away with increasing acceleration
Three different mass projectiles are launched from the top of a building each at different angles of elevation. Each particle has the same initial kinetic energy. Which particle has the greatest speed just as it impacts with the ground?
The one with the lowest mass.
An amount of energy is added to ice, raising its temperature from -10 C to -5 C. A larger amount of energy is added to the same mass of water, raising its temperature from 15 C to 20 C. From these results, what can we conclude?
The specific heat of ice is less than that of water
If the net work done on a particle is zero, which of the following statements must be true?
The speed is unchanged
Two particles collide, one of them initially being at rest. Is it possible for both particles to be at rest after the collision?
This can happen sometimes if the more massive particle was at rest
Stars originate as large bodies of slowly rotating gas. Because of gravity, these clumps of gas slowly decrease in size. The angular velocity of a star increases as it shrinks because of
conservation of angular momentum
Is it possible for the total mechanical energy of a moving particle to be negative?
d. yes
A large stone is resting on the bottom of the swimming pool. The normal force of the bottom of the pool on the stone is equal to the:
difference between the weight of the stone and the weight of the displaced water
Area on a P-V diagram has units associated with:
energy
What happens to a given mass of water as it is cooled from 4C to zero?
expands
If a fly collides with the windshiled of a fast-moving bus, which experiences the greater acceleration?
fly
As I use sandpaper on some rusty metal, the sandpaper gets hot because:
heat is flowing from the metal into the sandpaper.
Superposition of waves can occur
in all of the above.
According to the first law of thermodynamics, the sum of the heat gained by a system and the work done on that same system is equivalent to which of the following?
internal energy change
The object shown below has mass m and velocity v. The direction of its angular momentum vector with respect to an axis perpendicular to the page through point O is
into the page.
A heavily loaded boat is floating in a pond. The boat sinks because of a leak. What happens to the surface level of the pond?
it goes down
The absolute temperature of an ideal gas is directly proportional to which of the following properties, when taken as an average, of the molecules of that gas?
kinetic energy
A wave generated in a medium is a longitudinal wave when
molecular displacements are parallel to the wave velocity.
When an artery gets a constricted region due to plaque, how does the pressure in this region compare to the pressure in an unconstricted region adjacent?
n the constricted region the blood moves at a higher speed than in the unconstricted region resulting in a decreased pressure
Which best describes the relationship between two systems in thermal equilibrium?
no net energy is exchanged
A car is initially moving at 20 m/s east and a little while later it is moving at 10 m/s north. Which of the following best describes the orientation of the average acceleration during this time interval?
north of west
If you try to use a straw on the moon you would
not work
In a natural process heat flows from
objects with high temperature to objects with low temperature
A runner circles a track of radius 100 m one time in 100 s at a constant rate. The greatest change in his velocity from his starting velocity:
occurs one-half of the way around the track.
A hockey puck traveling at speed v on essentially frictionless ice collides with one end of a straight stick lying flat on the ice and sticks to that end. In this collision
only linear momentum and angular momentum are conserved.
For a simple harmonic oscillator which of the following pairs of vector quantities can't both point in the same direction?(The position vector is the displacement from equilibrium)
position and acceleration
The value of an object's acceleration may be characterized in equivalent words by which of the following?
rate of change of velocity
An ideal fluid flows through a horizontal pipe having a diameter that varies along its length. Does the sum of the pressure and kinetic energy perunit volume at differfent sections of hte pipe
remain the same as the pipe diameter changes
If a fly collides with the windshiled of a fast-moving bus, which experiences an impact force with a larger magnitude?
same for both
The gravitational force exerted on an astronaut on Earth's surface is 650-N down. When she is in the International Space Station, is the gravitational force on her
smaller
A heavily loaded boat is floating in a pond. The boat starts to sink because of a leak but quick action plugging the leak stops the boat from going under although it is now deeper in the water. What happens to the surface level of the pond?
stays the same
Which of the following is not a vector quantity?
temperature
A car and a large truck traveling at the same speed collide head-on and stick together. Which vehicle undergoes the larger chang in the magnitude of its momentum?
the change in magnitude of momentum is the same for both
Consider a child who is swinging. As she reaches the lowest point in her swing:
the tension in the rope is equal to her weight plus her mass times her acceleration
In a system with two moving objects, when a collision occurs between the objects:
the total momentum is always conserved.
The position of a particle is given by är i 8 2j 8 and its linear momentum is given by äp 4i 8 10j 8. Find its angular momentum.
-18k
Two vectors lying in the xy plane are given by the equations Aä 5i 8 2j 8 and B ä 2i 8 3j 8. The value of Aä B ä is
-19k
An object moves 20 m east in 30 s and then returns to its starting point taking an additional 50 s. If west is chosen as the positive direction, what is the sign associated with the average velocity of the object?
0
A student adds two vectors with magnitudes of 200 and 40. Which one of the following is the only possible choice for the magnitude of the resultant?
200
Two different dams are made with the same width and the same depth. Dam A holds back a large lake while Dam B holds back a small lake. Which dam has to be built more strongly?
they need to be the same
Consider a point on a bicycle tire that is momentarily in contact with the ground as the bicycle rolls across the ground with constant speed. The direction for the acceleration for this point at that moment is:
upward
A change in a physical quantity w having initial value wi and final value wf is given by which of the following?
wf − wi
The area under the force vs. displacement curve represents:
work
Of the following systems, which contains the most heat?
Systems do not contain heat.
It is possible for an object to have motion in the absence of forces on the object
T
It is possible to have forces on an object in the absence of motion of the object.
T
When applying the equations of kinematics for an object moving in one dimension, which of the following statements must be true?
The acceleration of the object must remain constant
A lump of clay is thrown at a wall. A rubber ball of identical mass is thrown with the same speed toward the same wall. Which statement is true?
The ball experiences a greater change in momentum than the clay.
