A radioactive isotope of lead has a half-life of 10.6 hours. A small sample of lead containing this isotope has a count rate of 8000 counts per
minute.
How long will it be before the count rate is 1000 counts per minute?
Time =
hours

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

A-4.60 μc charge is moving at a constant speed of 6.80×105 m/s in the +x−direction relative to a reference frame. at the instant when the point charge is at the origin, what is the magnetic-field vector it produces at the following points.

The velocity of car is 80.0 miles per hour. what is the velocity of car in meters per second? (1 km -0.621 miles) m/s