A 110-pound person pulls herself up 4.0 feet. This took her 2.5 seconds. How much power was developed?
2 answers:
Answer: Power developed by her is <u><em>0.32 hp</em></u>
Explanation:
Work done , W= Force(F) X Displacement (d) in the direction of force
Thus work done ,
Now 1.0 ft-lbf = 1.355 joules of energy
Therefore , work done, W= 440x 1.355 J = 596.2 J
Average Power ,
=>
We know 746 hp = 1.0 watts
=>
Thus average power developed by her is 0.32 hp
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Answer:
529.15 m/s
Explanation:
h = Maximum height = 70000 m
g = Acceleration due to gravity = 2 m/s²
m = Mass of sulfur
As the potential and kinetic energies are conserved
The speed with which the liquid sulfur left the volcano is 529.15 m/s
Answer:
Option B, 93 cm
Explanation:
An diagram of the seed's motion is attached to this solution.
This is very close to a projectile motion question. And the quantity to be calculated, how far along the grant a seed released would travel is called the Range.
And this would be obtained from the equations of motion,
First of, the height of the plant is related to some quantities of the motion with this relation.
H = u(y) t + 0.5g(t^2)
U(y) = initial vertical component of velocity = 0 m/s, H = height at which motion began, = 20cm = 0.2 m
That means t = √(2H/g)
The horizontal distance covered, R,
R = u(x) t + 0.5g(t^2) = u(x) t (the second part of the equation goes to zero as the vertical component of the acceleration of this motion is 0)
(substituting the t = √(2H/g) derived from above
R = u(x) √(2H/g)
Where u(x) = the initial horizontal component of the bomb's velocity = maximum initial speed, that is, 4.6 m/s, H = vertical height at which the seed was released = 20 cm = 0.2 m, g = acceleration due to gravity = 9.8 m/s2
R = 4.6 √(2×0.2/9.8) = 0.929 m = 0.93 m = 93 cm. Option B.
QED!
