Two trains are headed toward each other on the same track with equal speeds of 20m/s. When they are 2 km apart, they see each other and begin to decelerate. A.) If their accelerations are uniform and equal, what must their acceleration be in order to barely avoid a collision? b.) if only one car slows down with this acceleration (the other continuing with its original speed), how far will the decelerating train travel before it collides with he other train?

Aplane flying horizontally at an altitude of 1 mile and a speed of of 500mih passes directly over a radar station. find the rate at which the distance from the plane to the station is increasing when it is 2mi away from the station.

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b. b. at twice the distance, the magnitude of the field is 2b. c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.