Q2.7 Centripetal acceleration (S)
A space probe can withstand the stresses of a 20g acceleration. What is the minimum turning radius needed if its speed is 10-3c ? How long would it take to complete a 90∘ turn?
[velocity of light c=3×108ms-1]
Hint
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a bit more than the earth-moon distance.
Solution
According to Key Point 1.8 a body moving at uniform speed v in a circle of radius r exhibits an acceleration directed towards the centre of the circle (ie centripetal) of magnitude v2/r. Setting
The time to complete one quarter of a revolution like this is