Answer:
A. 243 N
Explanation:
Friction is the force that opposes the relative motion between systems that are in contact.
This friction force that opposes the motion of the oak chest across the oak surface will be equal and opposite to that exerted by the woman.
First find the normal force which is the force that would point directly upwards to support weight of the block.
Normal force, N= mg where m is the mass of the chest and g is the acceleration due to gravity.
Given m=40 kg and g=9.80 m/s²
N force=40×9.80 =392N
Then find the force of friction which is given by the formula;
<em>F=μN where μ is friction coefficient for the oak chest and N is the normal force on the chest</em>
Given <em>μ</em>=0.620 and N force = 392 N then it will be;
F=0.620× 392 =243.04 N
Answer : 243 N
Answer:
47.5kJ
Explanation:
Before climbing the cliff
At 2.
Answer:
<em>1.43 s.</em>
Explanation:
Using one of the equations of motion,
S = ut + 1/2gt².......................... Equation 1
Where S = height of the cliff, u = initial velocity, t = time, g = acceleration due to gravity.
<em>Note: When the rock begins to fall from the maximum height, u = 0 m/s, g = positive</em>
<em>Given: S = 10 m, u = 0 m/s</em>
<em>Constant: g = 9.8 m/s²</em>
<em>Substituting these values into equation,</em>
<em>10 = 0(t) + 1/2(9.8)(t²)</em>
<em>10 = 0 + 4.9t²</em>
<em>t² = 10/4.9</em>
<em>t² = 100/49</em>
<em>t = √(100/49)</em>
<em>t = 10/7</em>
<em>t = 1.43 s.</em>
<em>Thus the rock spend 1.43 s in air</em>
The ideal mechanical advantage of the screwdriver is 47
Explanation:
In this problem, the screwdriver acts as a lever.
The Ideal Mechanical Advantage (IMA) of a lever is given by:
where:
is the distance of the point of application of the input force from the fulcrum
is the distance of the output force from the fulcrum
In this problem, we have:
, since the fulcrum is 0.500 cm from the end
(the distance between the fulcrum and the point where are we holding the screwdriver)
Substutiting,
Learn more about levers here:
brainly.com/question/5352966
#LearnwithBrainly
The best method to use in prevention of self-demagnetization of a permanent magnet is by use of a keeper. Keepers were also commonly known as amateurs. They help in storing magnets safely, especially those that have low coercivity ( magnets that are extremely susceptible to stray fields).
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