Time, Speed And Distance

Speed, Distance & Time
• Speed = distance/time
• Time = distance/ Speed
• Distance = (Speed * Time)
• Distance = Rate x Time
• Rate = Distance/Time
• Convert from kph (km/h) to mps(m/sec): x km/hr=x∗(5/18) m/sec
• Convert from mps(m/sec) to kph(km/h): x m/sec= X*(18/5) km/h
• If the ratio of the speeds of A and B is a : b,
then the ratio of the times taken by then to
cover the same distance is :1/a : 1/b or b:a
• 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)
• When speed is constant distance covered by
the object is directly proportional to the time
taken. ie; If S₁=S₂ then D₁/D₂ = T₁/T₂
• When time is constant speed is directly
proportional to the distance travelled. i.e; If
T₁=T₂ then S₁/S₂=D₁/D₂
• When distance is constant speed is inversely
proportional to the time taken i.e if speed
increases then time taken to cover the
distance decreases. ie; If D₁=D₂ then S₁/S₂
= T₂/T₁
• If the speeds given are in Harmonic
progression or HP then the corresponding
time taken will be in Arithmetic progression
or AP
• If the speeds given are in AP then the
corresponding time taken is in HP
• If two objects are moving in same direction
with speeds a and b then their relative speed
is |a-b|
• If two objects are moving is opposite direction
with speeds a and b then their relative speed
is (a+b)

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Time and Work