Hello!
Work is equal to negative change in PE and PE=mgh and Power is change in work/change in time
So we have
56.1kg * 9.80m/s^2 * 16m = 8796.5 J of PE at top of run and -8796.5J of work done also
if it takes him 12s then we need to find the time gravity alone would bring him to the bottom. we get
16m=1/2at^2 and solving for t we get
t=sqrt(32/9.80m/s^2)=1.81s
so the difference in time is 12-1.8=11.2s
now we can find avg power=work/time = 8796.5J/11.2s = 785W or 785J/s
Hope this helps! Any questions please ask! Thank you!
Answer:
21.5°
Explanation:
Given,
Refractive index of water, n₁ = 1.33
Refractive index of polystyrene, n₂ = 1.49
Angle of reflection = ?
Angle of refraction = 19.1°
Using Snell's law
n₁ sin θ₁ = n₂ sin θ₂
1.33 x sin θ₁ = 1.49 x sin 19.1°
sin θ₁ = 0.366
θ₁ = 21.5°
According to law of reflection angle of incidence is equal to angle of reflection.
Angle of reflection = 21.5°
Answer:
1 sec
Explanation:
Horizontal distance (x) = 6m
Vertical distance (y) = 1.25m
Hang time is the duration the object is in the air before it reaches maximum height.
The time of free fall is given by
t = √2y/g
g = acceleration due to gravity
t = √(2*1.25)/9.8
t = √2.5/9.8
t = 0.5secs
Hang time = 2*0.5
= 1 sec
Answer:
a) 
b) 
Explanation:
Given:
height of water in one arm of the u-tube, 
a)
Gauge pressure at the water-mercury interface,:

we've the density of the water 


b)
Now the same pressure is balanced by the mercury column in the other arm of the tube:



<u>Now the difference in the column is :</u>


