Answer:
Explanation:
When the skier reaches the bottom of the slope , height lost by it
h = 50 sin32 m
= 26.5 m
potential energy lost
= mgh
Gain of kinetic energy
= 1/2 mv²
mgh = 1/2 mv²
v = √ 2gh
= √ (2x9.8 x 26.5)
= 22.8 m /s
b )
Let μ be the coefficient of kinetic friction required.
friction force acting
= μmg
work done by friction in displacement of d (40 m ) on horizontal surface
- μmg x d
This negative work will be equal to positive kinetic energy of the skier on horizontal surface .
= μmg x d = (1/2) m v²
μ = v² / (2 gd)
= 519.4 / (2 x 9.8 x 140 )
= .19
Answer:
Jedge = 0.076A/cm^2
Explanation:
If you want to know what is Jedge is convenient to use an integral. The total density current is given by:
(1)
But also, we have that the total current is
where we have used that 5mm=5*10^{-3}m.
By replacing (1) we obtain:
hope this helps!!
Answer:
Option C - the angle of refraction is greater than the angle of incidence
Explanation:
Snell's law of refraction states that;
n1 sinθ1 = n2 sinθ2
Where;
n1 is refractive index of incidence medium
θ1 is angle of incidence
n2 is Refractive index of refraction medium
θ2 is angle of refraction
For This question, n1 = 1.5 and n2 = 1.33
Thus;
1.5 sinθ1 = 1.33 sinθ2
Rearranging, we have;
sinθ1/sinθ2 = 1.33/1.5
We know from trigonometry, that sin 0 = 0 and sin 90 = 1. So, as θ approaches 0°, the value of sinθ decreases while as it approaches 90°,the value of sinθ increases.
Thus, by inspection, we can say that the value of the denominator is higher than the numerator.
Thus, θ2 is greater than θ1
So, the angle of refraction is greater than the angle of incidence
When you rub the balloons, it will take electrons away, which is negative. So, the balloons are negative
