a football is thrown directly toward a receiver with an initial speed of 18.0 m/s at an angle of 35 above the horizontal. at that instant, the receiver is 18.0 m from the quarterback. in what direction and with what constant speed should the receiver run to catch the football at the level at which it was thrown

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.

F500 j of energy were added to 1 kg of each of these samples, which would experience the least temperature increase?

Which of the following are considered noble gases? a. bromine b. neon c. argon d. chlorine