The normal force is always (underline, bold) is always perpendicular to the surface an object is sitting on. If the object is on an inclined plane, then the normal will not be vertical but it will be perpendicular to the angle of the incline.
The diagram below (left) shows a normal force (GH) that is not vertical, but it is perpendicular to the surface. The object on the right is the more usual normal a mass on a table top.
The vertical line on the right is the normal and it points up.
Answer:
(a) The horizontal ground reaction force
(b) The vertical ground reaction force
(c) The resultant ground reaction force
Explanation:
Given
John mass , m = 65 kg
Horizontal acceleration ,
Vertical acceleration ,
(a) Using Newton's 2nd law in horizontal direction
=>
Thus the horizontal ground reaction force
(b) Using Newton's 2nd law in vertical direction
=>
=>
Thus the vertical ground reaction force
(c) Resultant ground reaction force is
=>
=>
Thus the resultant ground reaction force
Answer: 7.5 rev/s
Explanation:
We are given the angular velocity a helicopter's main rotor blades:
However, we are asked to express this in the International Systrm (SI) units. In this sense, the SI unit for time is second (
):