Answer:
w=3.05 rad/s or 29.88rpm
Explanation:
k = coefficient of friction = 0.3900
R = radius of the cylinder = 2.7m
V = linear speed of rotation of the cylinder
w = angular speed = V/R or to rewrite V = w*R
N = normal force to cylinder
N=


These must be balanced (the net force on the people will be 0) so set them equal to each other.





There are 2*pi radians in 1 revolution so:

So you need about 30 RPM to keep people from falling out the bottom
The velocity (V) of a wave is the frequency (F) times the wave length (lambda):
V = F * lamda
lambda is the distance from crest to crest which is twice the distance from crest to trough.
=> lamba = 2 * 3.00 m = 6.00 m
F = number of waves / time = 13.0 waves / 20.2 s
Now you can plug in the values in the formula of V:
V = 6.00 m/wave* 13.0 waves / 20.2 s = 3.86 m/s
Answer: 3.86 m/s
Number three
They contain protons (positive), neutrons (negative), electrons (neutral) and all are in a nucleus which is part of an atom
Explanation:
It is given that,
Mass of platinum bar, m = 750 g
Length of the bar, l = 5 cm
Breadth of the bar, b = 4 cm
Width of the bar, h = 1.5 cm
Volume of the bar, 

We need to find the density of the platinum bar. The density of any substance is given by :



So, the density of the platinum bar
. Hence, this is the required solution.
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