Physics 1114
T/F: All measurements can be done with 100% accuracy.
False
T/F: If you swing a bucket of water fast enough in a vertical circle, at the highest point the water does not spill out. This happens because an outward force balances the pull of gravity on the water.
False
T/F: The coefficient of friction can be zero, meaning there is no friction between the two surfaces.
False
T/F: The term "centripetal force" refers to an actual force that you can label on a free-body diagram.
False
T/F: When finding the lower bound of the volume, you just subtract the accuracy of the instrument from the total volume.
False
T/F: When finding the magnitude of the sum of two vectors, you can directly add the magnitudes of the two vectors.
False
A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is ____________
Four times as much
The coefficient of static friction is always _________ the coefficient of kinetic friction.
Greater than
Two objects have equal kinetic energies. How do the magnitudes of their momenta compare?
Not enough information to decide
An egg falls from a bird's nest in a tree and feels no effects due to the air. As it falls, _____________
Only its mechanical energy is conserved
When comparing two values obtained experimentally, you should use ___________
Percent Difference
When comparing an experimental value to a known (theoretical) value, you should use ___________
Percent Error
According to Equation 9 (w2=(1/MR)mag - (fs/MR)) if you you plot w2 vs. mag, what should the graph look like?
Positive Slope, Straight Line, Y-intercept is Negative
A specifc pendulum has a period of T, given by the equation above. IF the angle is increased from 2 degrees to 4 degrees, the period will ___________
Remain the same
A specifc pendulum has a period of T, given by the equation above. IF the mass of the pendulum, m, is decreased, the period will _____________
Remain the same
A quantity that has only a magnitude with proper units is called a _________
Scalar
What are the units for the period of a pendulum from the equation above?
Seconds
For uniform circular motion, what is constant?
Speed (This may be wrong)
The frictional force that holds an object in place it called _____________ friction.
Static
Given the equation above, describe the graph that you would obtain if you plotted acceleration vs. the mass ratio.
Straight line through the origin
If you drop a feather and a penny in a vacuum (no resistance), which one would hit the ground first?
They will hit at the same time
A ball is thrown straight up. What are the velocity and acceleration of the ball at the highest point in its path?
v = 0, a = 9.8 m/s^2 down The ball reaches its highest point when its velocity is zero; the acceleration of gravity is never zero (it is always 9.8 m/s^2 downward)
Considering our pulley system with a mass falling at a constant acceleration, what should the general shape of its velocity vs. time graph look like.
A straight line
Suppose that block m = .050kg, sometime after reaching the base of the incline, undergoes a completely inelastic collision with the stationary block M = .075kg. Use the principle of conservation of linear momentum to determine the common speed of the blocks just after the collision. (carry the answer to one decimal place)
1.4 m/s
A ball whose momentum is p (magnitude) strikes a wall and bounces off with the same momentum (magnitude). The change in the ball's momentum (magnitude) is ____________
2p
Use the prrinciple of conservation of mechanical energy to find the speed of the block at the base of the incline. (carry the answer to one decimal)
3.4 m/s
The weight of 600 g of salami is __________
5.9 N
Considering our pulley system with a mass falling at a constant acceleration, what should the general shape of its position vs. time graph look like.
A curve with an increasing slope
A heavy dart and a light dart are launched horizontally on a frictionless table by identical ideal springs. Both springs were initially compressed by the same amount. Which of the following statements about these darts are correct? (There could be more than one correct choice.) A) The darts both have the same kinetic energy just as they move free of the spring. B) The lighter dart leaves the spring moving faster than the heavy dart. C) The heavy dart had more initial elastic potential energy than the light dart. D) Both darts move free of the spring with the same speed. E) Both darts had the same initial elastic potential energy.
A, B, E
The action and reaction forces referred to in Newton's third law of motion ____________
Act upon different objects
An object experiences no acceleration. Which of the following cannot be true for the object? A) Forces act on the object, but the forces cancel B) A single force acts on the object C) No forces act on the object
B
The figure shows scale drawings of four objects, each of the same mass and uniform thickness, with the mass distributed uniformly. Which one has the greatest moment of inertia when rotated about an axis perpendicular to the plane of the drawing at point P?
B
Two children, Ahmed and Jacques, ride on a merry-go-round. Ahmed is at a greater distance from the axis of rotation than Jacques. Which of the following are true statements? A) Jacques has a greater angular speed than Ahmed. B) Jacques and Ahmed have the same angular speed. C) Jacques has a smaller angular speed than Ahmed. D) Ahmed has a greater tangential speed than Jacques.
B & D
A measurable quantity is known as a ____________
Base Quantity
A force acts on an object that is free to move. If we know the magnitude and direction of the force and the mass of the object, Newton's second law of motion enables us to determine the object's: A) Weight B) Position C) Acceleration D) Speed
C
If two particles have equal momenta, are their kinetic energies equal?
No, except when their speeds are the same
When applying the equations of kinematics for an object moving in one dimension, which of the following statements must be true? A: The velocity of the object must always be in the same direction as its acceleration B: The position of the object must increase with time C: The acceleration of the object must remain constant D: The velocity of the object must remain constant
C
Which is the correct free-body diagram for the trolley just before it pulls into the center?
C
Which of the following quantities are units of momentum? (There could be more than one correct choice.) A) N X m B) kg X s/m C) kg X m/s D) N X s E) kg X m^2/s^2
C, D
What principles can you use to find the speed of the block at the base of the incline? (choose all that apply)
Conservation of mechanical energy and kinematics
Which one of the following statements is correct? A) "Mass", "Velocity", "Speed", "Your Age" are all scalar quantities. B) "Mass", "Velocity", "Speed", "Your Age" are all vector quantities. C) "Velocity" and "Speed" are vector quantities while "Mass" and "Your Age" are scalar quantities. D) "Velocity" is a vector quantity while "Mass", "Your Age" and "Speed" are all scalar quantities.
D
A specifc pendulum has a period of T, given by the equation above. IF the pendulum is moved from the earth where the g is 9/8 m/s2, to Jupiter where it is 26.0 m/s2, the period of the pendulum will _______________
Decrease
A quantity that has to be calculated is known as ____________
Derived Quantity
The acceleration of an object undergoing uniform circular motion is constant in ___________
Direction (This may be wrong)
Which of the following quantities are vectors? A) Displacement B) Weight C) Distance D) Velocity E) Mass F) Speed
Displacement, Weight, Velocity
If a completely elastic collision takes place, during the collision, what is conserved?
Energy, momentum, and mechanical energy are conserved
Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now double both masses and the separation of the balls, what will now be the magnitude of the attractive force on each one? A) 16F B) 8F C) 4F D) F
F
Use the equation and picture above to answer the questions in this quiz. A specifc pendulum has a period of T, given by the equation above. IF the length of the string, L, is increased, the period will _____________
Increase
If the force applied on an object is greater than the force of kinetic friction the object will travel with __________ velocity.
Increasing
If the graph is a straight line, what information can be obtained from the y-intercept?
It gives you the maximum force of static friction
The frictional force that slows an object down while in motion is called __________ friction.
Kinetic
The density of a substance is defined as ___________
Mass per unit volume (this may be wrong)
Which of the following quantities are scalar? A) Mass B) Displacement C) Speed D) Velocity E) Weight F) Distance
Mass, Speed, Distance
Two vectors have length A = 4.0m and B = 3.5m. What are the maximum and minimum magnitudes of their vector sum?
Maximum = 7.5m, Minimum = 0.5m
If an inelastic collision takes place, during the collision, what is conserved?
Momentum and energy are conserved
If a fly collides with the windshield of a fast-moving bus, which object experiences an impact force with a larger magnitude?
They experience the same force
Which one has larger kinetic energy: a 500-kg object moving at 40 m/s or a 1000-kg object moving at 20 m/s?
The 500 kg object
Given the equation above, the slope of the graph of acceleration vs. the mass ratio is __________
The acceleration due to gravity
Two forces produce equal torques on a door about the door hinge. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force has a greater magnitude?
The first force (at the midpoint)
The weight of an object is ___________
The force with which it is attracted to the earth
When finding the upper bound of the density, you put what number in the denominator?
The lower bound of the volume
If you drop a feather and a penny in air, which one would hit the ground first?
The penny
When two or more objects collide, it is always true that _____________
The total momentum of all the objects remains unchanged
If the force on an object is in the negative direction, the work it does on the object must be ___________
The work could be either positive or negative, depending on the direction the object moves
When a rigid object rotates about a fixed axis, what is true about all the points in the object?
They all have the same angular speed and angular acceleration
During World War I, Germany used a "Big Bertha" cannon to hurl shells into Paris 30 miles away. This gun also had a very long barrel. What was the reason for using a long barrel in these guns?
To allow the force of the expanding gases from the gunpowder to act for a longer time
What is the purpose of the friction rider?
To counter balance the kinetic friction in the system
T/F: Graphs in which the velocity curve crosses the time axis are the graphs in which the object undergoes a direction change.
True
T/F: The magnitude of static friction is always greater than the magnitude of kinetic friction.
True
T/F: Work done depends on the magnitude of the force, the magnitude of the displacement and the angle between the force and the displacement.
True
Water at the bottom of a container is ____________
Under the same pressure as the water on the top (this may be wrong)
The trolley moves in a horizontal circular path of radius R with constant speed v. This motion is called ______________
Uniform Circular Motion
A quantity that has both a magnitude with proper units as well as a directions is called a __________
Vector
According to kinematics (x=0.5g*t^2), the acceleration is dependent only upon ____________
Where the object is located
You throw a baseball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down.
Work is negative on the way up and positive on the way down
A vector points from the origin into the second quadrant of the xy plane. What can you conclude about its components?
X is negative and Y is positive