Answer:
0.54
Explanation:
Draw a free body diagram. There are 5 forces on the desk:
Weight force mg pulling down
Applied force 24 N pushing down
Normal force Fn pushing up
Applied force 130 N pushing right
Friction force Fnμ pushing left
Sum of the forces in the y direction:
∑F = ma
Fn − mg − 24 = 0
Fn = mg + 24
Fn = (22)(9.8) + 24
Fn = 240
Sum of the forces in the x direction:
∑F = ma
130 − Fnμ = 0
Fnμ = 130
μ = 130 / Fn
μ = 130 / 240
μ = 0.54
Answer:
It slowly decreases and the friction acting on it slowing it down becomes the bigger net force, if that makes sense :)
Explanation:
Answer:
Option D: More than 90
Explanation:
Thickness probably depends on temperature. The higher the temperature, the more aliens we expect to be thin.
Answer:
Explained
Explanation:
Michelson contrast is used for patterns where the distribution of bright and dark segments is nearly equal.
It is given by:
where I_max = maximum illumination and I_min = minimum illumination
we know that
typically, I_min = 54% of I_max (general standard)
or I_min = 0.54 I_max
putting this value in above equation to get m
this approximately corresponds to m = 0.3 or 30%
hence, 30% recommended as the minimum Michelson contrast
Since this is a horizontal path, we can neglect the force of gravity acting on the body. So in this case we have that the force of tension is equal to the centripetal force, because we have a circular path.
Fcp=T, where T is the force of tension and Fcp is the centripetal force.
m*(v²/R)=250 N, where m is the mass of the body and it is m=0.3 kg, v is the max speed of the body, and that is what we are looking for and R is the max length of the string and it is R=0.75 m.
We divide by m and multiply by R and we get:
v²=(250*R)/m, take the square root:
v=√((250*R)/m)=25 m/s
So the max speed of the body if the max tension is T= 250 N and its max length is R=0.75 m is V=25 m/s.
