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>
Answer:
i think the answer is B but im not sure
Answer:
C
Explanation:
Rocks with hotter temperatures sank to the bottom of the Earth. The rocks with the hottest temperature became the core and the rocks with the least amount of heat became the crust.
Hope this helps!
Answer:
Yes
Explanation:
Yes it is called the refractive index denoted by n
n=sin<i/sin<r
Explanation:
Given:
Solving for 
:
where:
Integrating to get 
with initial conditions 
:
Integrating to get x with initial conditions x(0) = 0:
When t=T:
