Question

A car of mass mo is moving with a velocity vo along a straight track. If in a time interval to magnitude of its velocity is increased by 200% and its direction of motion is reversed, then magnitude of change in its momentum in this time interval is equal to n find n.[Take n positive)​

Answer 1

Explanation:

Given :        Mass of the motorcar, M=1200kg

                   Initial velocity of the car, u=90 km/h=25 m/s              (∵1km/h=5/18m/s)

                   Final velocity of the car, v=18 km/h=5 m/s

                   Time taken          t=4 s 

ΔP=mv−mu

ΔP=1200×5−1200×25=−24000  kg m/s

v=u+at

5=25+a×4               

⟹a=−5  m/s2          (-ve shows retardation)

∣F∣=m∣a∣=1200×5=6000 N 

Answer 2

Answer:

A car of mass mo is moving with a velocity vo along a straight track. If in a time interval to magnitude of its velocity is increased by 200% and its direction of motion is reversed, then magnitude of change in its momentum in this time interval is equal to n find n.