Time, Speed and Distance
Basics:
Speed = Distance / Time
Time = Distance / Speed
Distance = Speed * Time
For conversion of Km/hr to m/sec and as well as m/sec to km/hr
- For km/hr to m/sec = we need multiply with 5/18
- For m/sec to km/hr = we need multiply with 18/5
If u need clear info about conversion you can comment below
Ex:-
1. A person crosses a 600 m long street in 5 minutes. what is his speed in km/hr?
Ans:
D= 600m
T= 5min
S=? in km/hr
In this, we can't do the direct calculation because speed in meters and Time in minutes so we need to convert anyone either speed into km or Time into sec or hr
- Time = 5*60
= 300sec
- Speed=Distance/Time
= 600/5
= 120
= 2 m/s
But this is not answer for the above question this is the mistake that most of the people doing in exams
Because it is m/sec but we need km/hr so we need to convert it.
km/hr= 2*(18/5)
= 72km/hr
2. If a person walks at 14 km/hr instead of 10km /hr, he would have walked 20km more. The actual distance traveled by him is?
Ans:
For the speed at 10 km/hr the assume distance D and as well as at 14 km/hr he would be walked 20km more So D2=D+20
Given Data :
D =D
T =T
D2= D+20
Here time for the both speeds are same so we can use the formula
(D/S1)=((D+20)/S2)Ans:
For the speed at 10 km/hr the assume distance D and as well as at 14 km/hr he would be walked 20km more So D2=D+20
Given Data :
D =D
T =T
D2= D+20
Here time for the both speeds are same so we can use the formula
by solving above 7D=5D+100
7D-5D=100 => 2D=100
Distance D= 100/2 => 50km
