A stationary police car emits a sound of frequency 1205 Hz that bounces off of a car on the highway and returns with a frequency of 1255Hz. The police car is right next to the highway, so the moving car is traveling directly toward or away from it. 1. How fast was the moving car going?
2. Was the car moving away or towards the police?
3. What frequency would the police car have received if it had been traveling toward the other car at 25.0m/s?

According to newton’s first law of motion, which force is expected to cause a body to accelerate?

Who was the first scientist to measure speed as distance over time?

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s. when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?