How do i find the change in velocity

A stationary police car emits a sound of frequency 1200 hz that bounces off a car on the highway and returns with a frequency of 1250 hz. the police car is right next to the highway, so the moving car is traveling directly toward or away from it.

Which materials have properties associated with both metals and plastics? polymers, ceramics, composites, woods

In which scenario is the least amount of work done on a crate? A) a force of 120 N moves it 25m. B) a force of 115 N moves it 26m. C) a force of 130 N move it 22 m. D) a force of 125 N moves it 27m.

What can be said about q and k immediately after an increase in temperature exothermic?

How much work is required to move an electron through a potential difference of 3.00 volts? (1) 5.33 * 10^-20 J (3) 3.00 J (2) 4.80 * 10^-19 J (4) 1.88 * 10^19 J

How does gravitational force and electric force compare?

There are two types of addiction, psychological and physical. A. True B. False

What two gases probably dominated precambrian earth's atmosphere?

a fast ball travels at about 161kilometers/hr if this fast ball could keep its speed how long would it take this ball to travel 0.15 terameters?

You are traveling upstream on a river at dusk. you see a buoy with the number 4 and a flashing red light. what should you do?