# physics test 2

What is a geosynchronous satellite? A satellite that stays above the same point on the equator.
At which of the following situation will you feel "weightless"? Fn = mg + maWhen you are in an elevator that moves with a downward acceleration of 9.8 m/s^2.
Which of the following is Kepler's first law? The path of each planet around the Sun is an ellipse with the Sun at one focus.
Which of the following is Kepler's second law? Each planet moves so that an imaginary line drawn from the Sun to the planet sweeps out equal areas in equal periods of time.
Which of the following is Kepler's third law? The ratio of the squares of the periods T of any two planets revolving around the Sun is equal to the ratio of the cubes of their mean distances from the sun.
Which of the following is the units of work? N*m
Which of the following equations calculate kinetic energy? 0.5 m * v^2
If a negative work is done to an object, how would the kinetic energy of the object change? decrease Wnet = ?KE
Which of the following situation does an object of 20 kg mass have the largest kinetic energy?a) when it has a 3.5 m/sb) when it is at retc) when it has a -7.3 m/s -7.3 m/s
When a person climbs a mountain, how does the gravitational potential energy change? increase
Which of the following equation gives you Gravitational Potential Energy on the surface of Earth? mgy
Which of the following equation calculates the spring force? -kx
If a spring has stiffness constant of k, and it is stretched a distance of x, what is the elastic potential energy of this spring? 1/2 kx^2
If a spring has stiffness constant of k, and it is COMPRESSED a distance of x, what is the elastic potential energy of this spring? 1/2 kx^2
Which of the following forces are conservative?a) friction force b) gravitationalc) tensiond) air resistancee) push by a person b) gravitational
The Elastic potential energy of a spring is PE = 0.5 k x^2, if the spring's stiffness constant (k) is doubled and it's stretched length (x) is halved, how would its potential energy change? its PE is halved
A ball is thrown straight up. At what point does the ball have the most energy? Ignore air resistance. Everywhere; the energy of the ball is the same at all of these points.
Can energy be created in nature? no
Can energy be transformed from one form to another in nature? yes
How can we deal with dissipative forces when using Work-Energy principle? We calculate the work done by dissipative forces.
Why is friction force a nonconservative force? The work done by friction force depends on the path
Which of the following units are NOT the units of power?a) Wb) hp c) N x m/sd) N x m N x m
Which equations gives the magnitude of linear momentum? mv
Which of the following is the units of momentum? J/s
Which of the following is NOT one of the four conservation laws?a) of energyb) of force c) of linear moment d) of angular momentum of force
Why can we assume the total momentum of the system conserves in collisions? Because the collisions normally happen in very short time.
oct 5 algebra questions top hat
During a sharp left turn you found yourself hitting the passenger door. What is the correct description of what is actually happening? the door is exerting a leftward force on you
You weight yourself on a scale inside an airplane that is flying with constant speed at an altitude of 20000 feet. How does your measured weight in the airplane compare with your weight as measured on the surface of the Earth? less than
oct 5 question 4
Is it possible to do work on an object that remains at rest? no
Can friction ever do positive work? yes
How does the work required to stretch a spring 2 cm compare with the work required to stretch it 1 cm? 4 times the work
if a spring has k = 405 N/mwhat is the work in compressing it 3.0 cm? .182 J