Two cars approaching each other , first car moves at 72 km/h ,the second car moves at 90 km/h, the first car started its siren with a frequency of 650 Hz. If the speed of the sound is 350 m/s, then what is the frequency of the sound heard by the driver of the second car from the police car?

What is the approximate amplitude of this wave a.10 seconds b.15 centimeters c.30 centimeters d.15 seconds

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?