Alight beam in air strikes the surface of water at an angle of 26° with the normal. when it enters the water it bends toward the normal, making an angle of 19° with it. the velocity of light in air is approximately 300,000 km/s. what is the approximate velocity of light in water?
sin i/ sin r= vi/vr
a. 77,197 km/s
b. 222,803 km/s
c. 278,437 km/s
d. 340,625 km/s

medium 1 is air, and its index of refraction rounds to 1.00. if the angle of incidence is 61° and the angle of refraction is 45°, what is the index of refraction of medium 2?
sin i/sin r = nr/ni
a. 0.89
b. 1.00
c. 1.24
d. 1.35

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.

Anne applies a force on a toy car and makes it move forward. what can be said about the forces acting on the toy car at the moment anne applies the force?

What is the equation for electrical work?