Atrain engineer drives a train 235 km north along a straight track. then he drives the train back south 126 km. finally, he drives north again 45 km to his final destination. what is the engineer's total magnitude of its displacement?

Two large, flat, horizontally oriented plates are parallel to each other, a distance d apart. half way betwween the two plates the electric field has magnitude e. if the separation of the plates is reduced to d/2 what is the magnitude of the electric field half way between the plates?

Determine the maximum r-value of the polar equation r =3+3 cos 0

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.