1. lifts it chest high
The force opposing to this action is the force due to
gravity. Therefore the work done is:
W1 = m g d
where m is mass of the barbell, g is gravity and d is displacement
2. holds it for 30 seconds
Work is a product of force and displacement, since there
is no displacement, therefore work done is zero.
W2 = 0
3. puts it down slowly
If the barbell was dropped, then it would simply be a free
fall. But since it was not, so the work done here is also equal to the weight
of the barbell times displacement:
W3 = m g d
We can see that W1 = W3, and since W2 = 0, therefore the answer
is:
<span>w3 = w1 > w2</span>
Explanation:
Contact force is any force that requires contact. An object that exerts a force on another object by touching it is exerting a contact force. Examples of contact force are friction and normal force.
Examples of a non-contact force are gravity and magnetism.
Answer:
True
Explanation:
Objects falling through the air experience a force of opposition called air resistance
Answer:
I believe its B and C
Explanation:
<u><em>If I'm wrong please tell me so I can correct my answer.</em></u>
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All will have a dominant trait I can't see the following statments