Answer:
Correct answer: A.) V = - 16.6 m/s down
Explanation:
Given:
V₀ = 3 m/s initial velocity
t = 2 seconds
g = 9.8 m/s²
V(t) = V(2) = ?
The movement described is a vertical upward shot
For velocity at any time is valid the next formula
V = V₀ - g · t
V = 3 - (9.8 · 2) = 3 - 19.6 = - 16.6 m/s down
Under condition that it has a enough drop height with respect to the ejection point.
God is with you!!!
Answer:
No
Explanation:
The work that can be turned into heat equals 100% and there is no thermodynamic law that says that cannot be.
by the wind and air flow in the wind
Answer:
F=126339.5N
Explanation:
to find the necessary force to escape we must make a free-body diagram on the hatch, taking into account that we will match the forces that go down with those that go up, taking into account the above we propose the following equation,
Fw=W+Fi+F
where
Fw= force or weight produced by the water column above the submarine.
to fint Fw we can use the following ecuation
Fw=h. γ. A
h=distance
γ=
specific weight for seawater = 10074N / m ^ 3
A=Area
Fw=28x10074x0.7=197467N
w is the weight of the hatch = 200N
Fi is the internal force of the submarine produced by the pressure = 1atm = 101325Pa for this we can use the following formula
Fi=PA=101325x0.7=70927.5N
finally the force that is needed to open the hatch is given by the initial equation
Fw=W+Fi+F
F=Fw-W+Fi
F=197467N-200N-70927.5N
F=126339.5N
Answer: Total work done on the block is 3670.5 Joules.
Step by step:
Work done:
With F the force, d the displacement, and theta the angle of action (which is 0 since the block is pushed along the direction of displacement, and cos 0 = 1)
Given:
F = 75 N
m = 31.8 kg
Final velocity 
In order to calculate the Work we need to determine the displacement, or distance the block travels. We can use the information about F and m to first figure out the acceleration:
Now we can determine the displacement from the following formula:
Here, the initial displacement is 0 and initial velocity is also 0 (at rest):
Now we still have "t" as unknown. But we are given one more bit of information from which this can be determined:
(using vf as final velocity, and tf as final time)
So it takes about 6.44 seconds for the block to move. This allows us to finally calculate the displacement:
and the corresponding work:
