Explanation:
Without the metric system, we'd have a different International System of Units, the metric system is important because 1mm is 0.1cm, 1 cm is 0.01m, with the imperial system the conversion is tedious. The most important feature of the metric system is its base in scientific fact and repeatable standards of measurement
If it is stationary, its not moving. there is no movement
Measured reading is 1.65 kg
actual reading was 1.72 kg
error in the reading is 1.72 - 1.65 = 0.07 kg
Now percentage error is given as



<em>so this is -4.1% error as the measured reading is less than the actual value</em>
It's a normal force exerted by the floor. It balances the gravitational force. Option A is correct. The normal force is balanced by the gravitational force.
<h3>What is the friction force?</h3>
It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N). Mathematically it is defined as the product of the coefficient of friction and normal reaction.
On resolving the given force and accelertaion in the different components and balancing the equation gets components in the y-direction.
The normal force is balanced by the gravitational force. It's a normal force exerted by the floor. It balances the gravitational force.
Hence, option A is correct.
To learn more about the friction force refer to the link;
brainly.com/question/1714663
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