What are some human causes for global warming?
1 answer:
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Answer:
a) , b)
Explanation:
a) According the Archimedes' Principle, the buoyancy force is equal to the displaced weight of surrounding liquid. The mass of the coal in the barge is:
b) The submersion height is found by using the equation derived previously:
The final submersion height is:
Answer:
a) W₁ = - 127 J
, b) W₂ = 148.18 J, c) = 3.43 m/s and d)
= 3.43 m / s
Explanation:
The work is given the equation
W = F. d
Where the bold indicates vectors, we can also write this expression take the module of each element and the angle between them
W = F d cos θ
They give us displacement, let's use Newton's second law to find strength, like the block has an equal acceleration (a = g / 7). We take a positive sign down as indicated
W-T = m a
T = W -m a
T = mg -mg/7
T = mg 6/7
T = 3.6 9.8 6/7
T = 30.24 N
Now we can apply the work equation to our problem
a) the force of the cord is directed upwards, the displacement is downwards, so there is a 180º angle between the two
W₁ = F d cos θ
W₁ = 30.24 4.2 cos 180
W₁ = - 127 J
b) the force of gravity is directed downwards and the displacement is directed downwards, the angle between the two is zero (T = 0º)
W₂ = (mg) d cos 0º
W₂ = 3.6 9.8 4.2
W₂ = 148.18 J
c) kinetic energy
K = ½ m v²
Let's calculate speed with kinematics
² = vo² + 2 a y
v₀ = 0
a = g / 7
² = 2g / 7 y
= √ (2 9.8 4.2 / 7)
= 3.43 m/s
We calculate
K = ½ 3.6 3.43²
K = 21.18 J
d) the speed of the block and we calculate it in the previous part
= 3.43 m / s