TIME AND DISTANCE -> IMPORTANT FACTS AND FORMULA E
1. Speed = Distance
Time,
Time=Distance
Time=Distance
2. x km/hr = [x*5/18] m/sec.
Note:Mind calculation to convert kmph into mps?
I explain it with help of example,
Ex.1:
convert 108kmph into mps?
sol:
simple technic is,
1.Multiply 90 with 10
2. consider 900-->36 sec
3.then it becomes 30-->1sec
4. final answer is
90kmph=30m/s
Ex.2:
convert 108kmph into mps?
sol:
1.Multiply 108 with 10
2. consider 1080-->36 sec
3.then it becomes 30-->1sec
4. final answer is
108 * kmph=30m/s
3. If the ratio of the speeds of A and B is a:b, then the ratio of the times taken by them to cover the same distance is 1/a : 1/b or b:a.
4. x m/sec = [x*18/5] km/hr.
Mind calculation to convert m/s into kmph?
I explain it with help of example,
Ex.1:
convert 30m/s into kmph?
1.30 m —— 1 sec
2. ? m —— 36 sec
1080m —->36 sec
3.So 1080/10 —-> 108 kmph
5. Suppose a man covers a certain distance at x km/hr and an equal distance at y km/hr. then, the average speed during the whole journey is [2xy/x+y] km/hr.
Example 1:
Ram can cover a certain distance in 1 hr 30 min. By covering two third of the distance at 4 kmph and the rest at 5 kmph. Find the total distance covered ?
sol: Let the total distance be x km then:
Example 1:
Ram can cover a certain distance in 1 hr 30 min. By covering two third of the distance at 4 kmph and the rest at 5 kmph. Find the total distance covered ?
sol: Let the total distance be x km then:
Ex 2. Walking at 4 / 5 of its normal speed, a school bus is 10 minutes late. Find its usual time to cover the journey.
Solution : New Speed = 4 / 5 of original speed,
since the speed and time has inverse relation so,
New Time taken by bus = 5 / 4 of the normal time
( 5 / 4 of usual time ) - ( usual time ) = 10 min.
1 / 4 of the normal time = 10 min
normal time = 40 min
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