The distance-time graph of two trains A and B is given below. The trains start simultaneously in the same direction.

(i) How much ahead of A is B when the motion starts?

(ii) What is the speed of B?

(iii) When and where will A catch B?

(iv) What is the difference between the speeds of A and B?

(v) Is the speed of both the trains uniform or non uniform? Justify your answer.

Asked by Topperlearning User | 15th Jun, 2016, 10:31: AM

Expert Answer:

begin mathsize 12px style left parenthesis straight i right parenthesis space straight B space is space 100 space km space ahead space of space straight A.
left parenthesis ii right parenthesis space Speed space of space straight B equals QR over PR equals fraction numerator 150 minus 100 over denominator 2 minus 0 end fraction equals 25 space km divided by straight h
left parenthesis iii right parenthesis space straight A space will space catch space straight B space at space point space straight Q space after space 2 space hrs space and space at space straight a space distance space of space 150 space km.
left parenthesis iv right parenthesis space Speed space of space straight A equals QS over OS equals fraction numerator 150 minus 0 over denominator 2 minus 0 end fraction minus 75 space km divided by straight h
space space space space space space space Speed space of space straight B equals 25 space km divided by straight h
space space space space space space space So comma space the space difference space is space 50 space km divided by straight h.
left parenthesis straight v right parenthesis space Uniform space speed comma space since space they space travel space equal space distances space in space equal space interval space of space time semicolon
space space space space space space Both space are space striaght space line space graphs. end style

Answered by  | 15th Jun, 2016, 12:31: PM