Avehicle has an initial velocity of 30 meters per second. 30 seconds later it is traveling at a velocity of 60 meters per second. what is the acceleration of the vehicle?

a) 10 meters/second/second in the opposite direction of travel
b) 10 meters/second/second in the same direction of travel
c) -1 meter/second/second in the same direction of travel
d) 1 meter/second/second in the same direction of travel

The current in a hair dryer measures 11 amps. the resistance of the hair dryer is 12 ohms. what is the voltage?unit:

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •  

Four point charges each having charge q are located at the corners of a square having sides of length a. find symbolic expressions for the following. (a) the total electric potential at the center of the square due to the four charges (use any variable or symbol stated above along with the following as necessary: ke.) vtotal= (b) the work required to bring a fifth charge p from infinity to the center of the square (use any variable or symbol stated above along with the following as necessary: w=