A fuse melts to protect a circuit.
Total resistance= 7.75+15.5+21.7=44.95
Current = 15V/44.95=0.334A
Depending on which type of motor you're talking about, but the first 3 are true. A stronger magnetic field in a DC motor will slow it down but increase its torque.
The amount of current in the motor will control the magnetic fields and therefore affect the speed (and torque). In an induction motor, the rotational speed is given by

where f is the line frequency and p is the number of poles. Thus fewer poles makes it go faster.
Answer:
polystyrene is a good insulater so less heat will escape from the cup and it will keep it warm.
the cup helps it become more insulated
Answer:
Explanation:
Given
distance traveled by Passenger train is 
distance traveled by Freight train is 
Both take same time to travel
suppose speed of freight train is x mph
so speed of passenger train is 20+x mph
we know time




speed of passenger train