A train consists of a 50 Mg engine and three cars, each having a mass of 30 Mg . If it takes 90 s for the train to increase its speed uniformly to 45 km/h , starting from rest, determine the force T, developed at the coupling between the engine E and the first car A. The wheels of the engine provide a resultant frictional tractive force F which gives the train forward motion, whereas the car wheels roll freely. Express your answer with the appropriate units.

How many molecules are present in 3 mols of silicon dioxide (sio2)?

Another word for electromagnetic energy is a. heat b. force c. matter d. radiation

Suppose that a mass of 2 kg is attached a spring whose spring constant is 50. the system is damped such that b = 12 . the mass is set in motion with an initial velocity of -8 m/s at a position 0 meters from equilibrium. set up and solve a differential equation that models this motion. write your solution in the form a cos ( ω t − α ) where α is a positive number. use your solution to fill in the information below: what is the amplitude of the motion? what is the value of ω ? what is the phase shift?