SOLUTION: All the scene of a accident police can estimate the speed a car had been travelling by the length of the skid mark . One formula used for this purpose is V = -7 + 8.2 √(d) wh

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Question 752500: All the scene of a accident police can estimate the speed a car had been travelling by the length of the skid mark . One formula used for this purpose is V = -7 + 8.2 √(d) where v is the speed in the kilometers per hour and d is the length of the skid mark in metres.
a) Solve the formula for d
b) how long would the skid mark of the car breaking from 60 kilometre per hour?
c) What was the speed of the car if the length of the skid mark is 50 metres?
Can you please help me out? Thanks so much in advance:)
Can you please show the steps it would really help me understand:)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
All the scene of a accident police can estimate the speed a car had been travelling by the length of the skid mark .
One formula used for this purpose is V = -7 + 8.2 √(d) where v is the speed in the kilometers per hour and d is the length of the skid mark in metres.
a) Solve the formula for d
8.2*sqrt(d) = V+7
sqrt(d) = (V+7)/8.2
d = [(V+7)/8.2]^2
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b) how long would the skid mark of the car breaking from 60 kilometre per hour?
d = [(60+7)/8.2]^2 = 66.76 meters
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c) What was the speed of the car if the length of the skid mark is 50 metres?
V = -7 + 8.2sqrt(d)
V = -7 + 8.2*sqrt(50)
V = -7+ 57.98
Velocity = 50.98 km/hr
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Cheers,
Stan H.
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