Answer to Question #66787 in Mechanics | Relativity for Emmanuel chinonye

Question

1) A lorry driver pushes of horizontal with a speed of 20m/s from the edge of a platform that is 10m above, the surface of the water.(a)at what horizontal distance from the edge of the platform is the driver 0.80sec after pushing off. (b) at what vertical distance above the surface of the water is the driver just then.(c) at what horizontal distance from the platform does the driver strike the way.
2) An astronaut is located in an horizontal centrifuge at a radius of 50m.(a)what is the astronaut speed if the centripetal acceleration has magnitude of 7.0g (b) what is the period of the motion

Answer 1

1) a) The distance can be calculated as h = gt^2/2 = 9.8*0.8^2/2 = 3.1 m.
b) It is 10 m - 3.1 m = 6.9 m
c) The time for 10 m height is t = sqrt(2*h/g) = 1.4 sec and the distance is 20 m/s*1.4 s = 28 m
2) a) The acceleration is a = v^2/R and v = sqrt(aR) = 59 m/s.
b) T = l/v = 2*3.14R/v = 5.3 sec.