Atrain consists of a 60 mg engine and three cars, each having a mass of 30 mg . if it takes 75 s for the train to increase its speed uniformly to 42 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.

this means that the temperature of both substances will be equal

f is prop to m1xm2 double m1 double force

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.