Physics
posted by Anonymous .
a)An object on a frictionless surface forms an angle of 27° with the horizontal. The object is pushed by a horizontal external force such that it moves with a constant speed. If the mass of the object is 72.3 kg, calculate the magnitude of the external force.
b)What is the magnitude of the force exerted by the inclined surface on the object?

Weight = 72.3*9.8 = 708 N
component of weight normal to surface = 708*cos 27 = 631 N
component of weight down slope = 708 sin 27 = 322 N
Push force = F
component of push up slope = F cos 27
so
F cos 27 = 322 N
F = 361 N
component of F Normal to surface = 361 sin 27 = 164 N
total normal force on slope = 164+631 = 795 N 
Soo what is a) supposed to be 164 and is b) 795?

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