A train whistle is 580 Hz when stationary. It is coming toward you at 18.8 m/s. What frequency do you hear?
(Speed of sound = 343 m/s) (Unit=Hz)

Although light from the sun appears white, it is actually made up of a lot of different colors. this portion of the electromagnetic spectrum, we call white light is referred to as within the electromagnetic spectrum.

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.