Four different observers are standing in a straight line on a street and hear a siren from a police car. Each person recorded their observations in the chart shown. If the people are all lined up on the street at different blocks, and the police siren starts at block 3, which statement describes what block each person is standing at? Wycleff is on block 1, Lilly is on block 4, Quincy is on block 12, and Emilia is on block 17. Lilly is on block 1, Wycleff is on block 4, Quincy is on block 12, and Emilia is on block 17. Lilly is on block 1, Wycleff is on block 4, Emilia is on block 12, and Quincy is on block 17. Wycleff is on block 1, Lilly is on block 4, Emilia is on block 12, and Quincy is on block 17.

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.

The speed of light can be used to measure the

If the spring constant k of a pogo stick is 3500 n m and the weight of the person on the pogo stick is 700 n, how much is the spring in the botom of the pogo stick compressed?