9th Class Science Time and Motion Question Bank Motion HOTS Subjective Problems

  • question_answer
    A car travelling at 60 km/h overtakes another car travelling at 42 km/h. Assuming each car to be 5.0 m long, find the time taken during the overtake and the total road distance used for the overtake.

    Answer:

    If one over takes the other, then time by the both are same, = t If we consider the length of the cars, the difference of distance travelled by the both cars \[=5+5=10m\] Velocity of car \[A\,\,\And \,\,{{V}_{A}}=60km/h\] \[=60\times \frac{5}{18}=\frac{50}{3}m/s\] Velocity of car B, \[{{V}_{B}}=42km/hr\] \[=42\times \frac{5}{18}=\frac{35}{3}m/s\] distance travelled by car A \[{{S}_{A}}={{V}_{A}}\times t\frac{50}{3}t\] distance travelled by car B \[{{S}_{B}}={{V}_{B}}\times t\frac{35}{3}t\] \[\therefore \frac{50}{3}t-\frac{35}{3}t=10\Rightarrow t\left[ \frac{50}{3}-\frac{35}{3} \right]=10\] Since the fastest car travelled more distance, the total road distance used for the overtake \[={{V}_{A}}\times t+5m=\frac{50}{3}\times 2+5=38.33m=38m\]


You need to login to perform this action.
You will be redirected in 3 sec spinner