Answer:
<em>The angle introduces an error on the mesure of the weight</em>
Explanation:
<u><em>Weight and Normal Forces</em></u>
When an object is resting on a horizontal surface, its weight is directed downwards and the normal force has the same magnitude and opposite direction, i.e. directed upwards. When some angle α exists between the surface and the horizontal plane, the scale keeps 'feeling' the Normal force, but it's not equal to the weight anymore, but to the perpendicular component of the weight to the surface where the scale is placed. It can be found that the component of the weight is m.g.cosα
If, for example
, the real measure is

That is, 98.5% of the correct weight. So it's important to measure weight on horizontal surfaces
Answer:
The net force acting on the chair is 8 newtons, and the chair moves toward the left.
Explanation:
We can better understand this problem if we analyze it through a free body diagram. This free body diagram is attached as an image.
If we make a sum of forces acting over the chair we can find -20 + 12 = -8 [N]
The minus sign indicates that the chair is moving to the left.
Answer:
The concave mirror is a converging mirror so that it is used for many purposes, It is used as a torch to reflect the light, It is used in the aircraft landing at the airports to guide the aeroplanes, It is used in shaving to get an enlarged and erect image of the face.
Explanation: