Term
Could the work done on an object result in an increase of kinetic energy? 

Definition


Term
Could you do no net work and yet get tired? 

Definition
Yes, for instance when lowering and lifting the same object many times 


Term
A conservative force in physics is 

Definition
a force that only depends on the initial and final points 


Term
The gravitational potential energy is (m is mass, h is height) 

Definition


Term
Is friction a conservative force? 

Definition


Term
The gravitational force between two masses applies 

Definition
for any masses in the universe 


Term
The drag forces and resistive forces are 

Definition


Term

Definition
the constant speed at which an object moves in a fluid 


Term
Resistive forces on regular objects (rocks, raindrops, etc) in air are dominated by 

Definition


Term
For objects moving in liquids you are normally in regime 

Definition


Term
The direction of the force respect to the increase of potential energy is 

Definition


Term
If we knew the potential energy could we get the force? 

Definition


Term
From the energy equation in a spring mass system we can derive 

Definition
the equation for simple harmonic motion 


Term
An object moves near the bottom of a frictionless spherical bowl. If the object starts from rest and you let it go the motion would be 

Definition


Term
In an oscillating pendulum is the tension doing any work? 

Definition


Term
Why did the smaller circular track fail the prediction for small oscillations, while the large air track did not? 

Definition
the ball roll in the small track while the mass did not roll in the large one 


Term
The velocity to escape the gravitational pull of the Earth and never fall back is 

Definition


Term
If the total energy available to an object that wants to leave the Earth is less than zero we call the possible orbit 

Definition


Term
The period of rotation of the space shuttle orbit around the Earth was 

Definition


Term
A person is riding a bicycle. The power required to maintain certain speed is force times velocity. The force due to air friction is the air drag and it is proportional to the velocity squared. The power needed to double the speed is 

Definition


Term
How many watts per square meter does the Sun provide to the Earth? 

Definition


Term
If a particle changes its momentum 

Definition
a force must have acted on it 


Term
The change of total momentum of a system of particles is equal to 

Definition
the sum of external forces only 


Term
If the net force on a system of particles is zero, we say that the net momentum is 

Definition


Term
In collision of particles with no outside forces we say that 

Definition
the kinetic energy is not always conserved 


Term
The center of mass is at point 

Definition
that behaves as if all the mass of the object was concentrated there 


Term
Two ball with same mass collide with each other in an elastic collision. One ball was at rest before collision, what happens after collision? 

Definition
the ball at rest moves while the incoming ball stops 


Term
A collision of particles as seen from the center of mass has momentum zero 

Definition
before and after collision 


Term
As seen from the center of mass, in an elastic collision, the speeds of particles after collision are: 

Definition
the same as before but with opposite signs 


Term
The ballistic pendulum is used to measure 

Definition


Term

Definition


Term
The engines in rocket Saturn spit out gas at the speed of 

Definition


Term
Two identical rockets with burn the same amount of fuel and increase their speed by the same amount; one started from rest and one was already moving. Which rocket increases its kinetic energy more? 

Definition
the rocket that had an initial speed 


Term
n circular motion, the tangential acceleration results in a change of 

Definition


Term
The moment of inertia for a set of masses is the sum of 

Definition
each mass times the distance square of this mass to the axis of rotation 


Term
Can energy be stored in a rotating object? 

Definition


Term
The Crab pulsar rotational speed is 

Definition


Term
The angular momentum of a pointlike object depends on 

Definition
the location of the origin of observer 


Term
What makes the angular momentum of a pointlike object change as seen by the same observer? 

Definition


Term
If an object spins around its center of mass then its the angular momentum is 

Definition
the same for all observers located anywhere 


Term
If an object is free of external torques and is spinning, what would happen if the object increases, by any means, its moment of inertia? 

Definition


Term
A star collapses after it runs out of nuclear fuel. What could happen to it? 

Definition
it could be come a white dwarf, neutron star or a black hole 


Term
The angular momentum of a pointlike object changes if there is 

Definition


Term
The angular momentum of a meter stick about the center of mass is 

Definition
the same for all centers of rotation 


Term
A ruler is hit at a point away from its center of mass. After the hit the center of mass will move 

Definition


Term
A hula hoop is made to oscillate about a point at its edge. The period of oscillation does not depend on 

Definition


Term
The general orbit of a planet around the Sun is 

Definition


Term
Kepler found that planets move so that 

Definition
they trace equal areas in equal times 


Term
If for an orbit of a satellite or planet the total energy is negative we have 

Definition


Term
If a sandwich is in a circular orbit and we want to change it to another orbit by slowing it down in a direction tangent to the circle the period of the sandwich will 

Definition


Term
f an object that emits light approaches you its as seen by you light is 

Definition


Term
What fraction of the stars are binary? 

Definition


Term
Inside the event horizon of a black hole 

Definition
an object is trapped forever 


Term
When an object is in pure roll the speed of the center of mass is 

Definition
equal to the angular speed times radius 


Term
Two solid cylinders of the same mass, but one is smaller than the other, roll down an inclined plane, which one gets to the bottom first? 

Definition
they arrive at the same time 


Term
The angular momentum when changing moves in the direction 

Definition


Term
A bicycle wheel is spinning about its axis. If we support the wheel with a string at the end of one handle, what would happen? 

Definition
the wheel will precess (rotate) about the axis of the string 


Term
The spin angular momentum has the property of 

Definition


Term
What are the conditions for equilibrium of a rigid body? 

Definition
sum of forces and sum of torques both equal zero 


Term
A ladder is set on the floor near a wall. The ladder is at a critical angle so that it is ready to slide. A person steps at the bottom of the ladder then the ladder becomes 

Definition


Term
If you have a tube with and a rope wrapped around it so that the ends of the rope support a load each. Due to the friction the rope experiences with the tube we could 

Definition
put a very large load on one end of the rope and small load on the other 


Term
If you have an object with random shape. How could we find its center of mass? 

Definition
Find the point where two vertical equilibrium lines meet 


Term
A ropewalker to be very stable could use a long bent bar with extra weight at the ends so that 

Definition
the center of mass is below the rope 

