a +5mC at rest is 10 cm away from a+100mC stationary charge. (i) calculate the electric potential energy between the two charges. (ii) what is the electric potential energy when the +50 mC is 52cm away from the other charge? (iii) how much work was required to move the charge from 10cm to 50cm away from the stationary charge? (iv) what is the final speed of +5mC when it's 50cm away?

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Astronomers discover an exoplanet (a planet of a star other than the sun) that has an orbital period of 3.87 earth years in its circular orbit around its sun, which is a star with a measured mass of 3.59 x 1030 kg. find the radius of the exoplanet's orbit.

What is the momentum of a 2 kg object moving at 15 meters per second