TSD Flashcards
Speed xy
Equal distance
Average speed
2 x y / X + y
Three different speeds equal distance
Xyz/xy+yz+zx
Certain speed x y
Time interval same
Average speed is
X+y /2
Certain speed x y
Time interval same
Average speed is
X+y+z/3
Ratio of speed
X:y
Ratio of time
1/x:1/y
Bodies moving in same direction
X greater than y
Speed
(X -y) km/hr
Train and stationary object of no length or pole or standing man or a building
Speed of the train
Length of the train/time taken to cross the stationary object
Train (l) and stationary object (a) with certain length or another standing train bridge platform
Time taken
Speed of the train
Length of the train + length of object/ time taken to cross the object
Train and moving object of no length or a man moving
Same direction (x-y)
speed
Length of the train/time taken to cross each other
Train and moving object of no length or a man moving
Same direction (x+y)
speed
U
Train and moving object of certain length
Time taken l+a
Same direction x-y
Opposite direction X + y
Length of t1 + t2/time taken to cross each other
2 moving trains
if two train starts at the same time from point A B towards each other and after crossing they take a and b second in reaching B and a respectively
A speed : B speed is
√b:√a
Downstream means
Boat and stream are in same direction
Upstream means
Boat and stream are in different directions
Still water motion
Object is moving water is still
Uniform speed
X is speed of boat
y is speed of stream
Speed of boat with stream
Downstream
X + y kilometre per hour
X is speed of boat
y is speed of stream
Speed of boat against stream
Upstream
X - y kilometre per hour
One boat is moving downstream speed of water adds the speed of boat and when the boat is moving upstream speed of water reduces the speed of boat
Haha
Speed of downstream is a
Speed of upstream is B
Rate of stream
(A-B/2) km/hr
Speed of downstream is a
Speed of upstream is B
Speed of still water
(A+B/2) km/hr
Speed of downstream is a
Speed of upstream is B
Average speed
2ab/a+b
