Answer:
<em>The force of kinetic friction between Kiera and the floor is 9.24 N</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in rough surfaces, it loses acceleration and/or velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
Where μ is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W
Thus, the friction force is:
Kiera, the W=330 N girl steps in water that has a coefficient of friction of μ=0.028 with the floor.
The kinetic friction force is:
Fr = 0.028*330
Fr = 9.24 N
The force of kinetic friction between Kiera and the floor is 9.24 N
Element. element cannot be simplerfide
Answer: 
Explanation:
Given
Intensity must be reduced by a factor of 6
Intensity is given by 
Substitute 
by 
So, the disk must be rotated by an angle of .
Ok, this is a 2d kinematics problem, the falls 14 m part is confusing, I think it means in the x direction, but you don't need it anyway.
If we know it goes 4m into the air, we know d = 4m (height of wall), we also know the acceleration a=-9.8m/s^2 (because gravity) and that the vertical velocity when it just clears the wall will be 0 m/s, which we'll call our final velocity (Vf). Using Vf^2 = Vi^2 +2a*d, we can solve this for Vi and drop Vf because it's zero to get: Vi = sqrt(-2ad), plug in numbers (don't forget a is negative) and you get 8.85 m/s in the vertical direction. The x-direction velocity requires that we solve the y-direction for time, using Vf= Vi + at, we solve for t, getting t= -Vi/a, plug in numbers t= -8.85/-9.8 = 0.9 s. Now we can use the simple v = d/t (because x-direction has no acceleration (a=0)), and plug in the distance to the wall and the time it takes to get there v = (4/.9) = 4.444 m/s, this is the velocity in the x direction, we use Pythagoras' theorem to find the total velocity, Vtotal = sqrt(Vx^2 + Vy^2), so Vtotal = sqrt(8.85^2+4.444^2) = 9.9m/s. Yay physics!
Density = mass / volume
D = 89 / 10.0
D = 8.9 g/cm³
hope this helps!
