Two charges are located on the positive x-axis of a coordinate system, as shown in figure 2.8.
Charge q1=2nC is 2cm from the origin, and
charge q2=-3nC is 4cm from the origin. What is
the total force exerted by these two charges on a
charge q3=5nC located at the origin?

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.

What is magnetic flux? explain faraday's law of induction.

Which quantities are scalars? choose all that apply a. distance b. speed c. acceleration d. velocity