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:
yeah I'm Pretty sure it's b
Answer:
n = c/v = (3.00 x 108 m/s)/(2.76 x 108 m/s) = 1.09. This does not equal any of the indices of refraction listed in the table.
Deposition:
- when a gas changes directly to a solid
- latent heat is released
- physical change, NOT a chemical change
Answer:
63.57 kg
Explanation:
weight = 140 lbs
Let the mass is m.
1 lbs = 4.45 N
The weight of an object is defined as the force with which our earth attracts the body towards its centre.
Weight is the product of mass of the body and the acceleration due to gravity of that planet.
W = m x g
On earth surface g = 9.8 m/s^2
Now convert lbs in newton
So, 140 lbs = 140 x 4.45 = 623 N
So, m x 9.8 = 623
m = 63.57 kg
Thus, the mass is 63.57 kg.