PLS HELP 1.) When there are equal forces from opposite directions acting on an object, the forces are said to be which of the following? (4 points)

A.) Positive

B.) Negative

C.) Balanced

D.) Gravitational

2.) If you want to cause an object to move, what should you do? (4 points)

A.) Apply balanced forces.

B.) Apply neutral forces.

C.) Apply potential forces

D.) Apply unbalanced forces.

Aroller coaster car moving at a velocity of 30 meters/second has a momentum of 2.5 x 10^4 kilogram meters/second. what is its mass?

Calculate the kinetic energy of earth due to its spinning about its axis. krot = j compare your answer with the kinetic energy of the orbital motion of earth's center of mass about the sun. assume earth to be a homogeneous sphere of mass 6.00 1024 kg and radius 6.40 106 m. the radius of earth's orbit is 1.50 1011 m.

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?