Answer:
0.2687 approximately 0.27
Explanation:
Diameter = 0.320
Speed = 40.0 rev/min
We are required to find coefficient of static friction between friction and button
The radius can be calculated as
0.320/2
= 0.160m
Then we have the rotational speed w = 40rev/min x 2pi/60
= 4.19 rad/s
umg = mrw²
u = mrw²/mg
u = rw²/g -------(1)
g = 9.8
When we put values into equation 1
0.150m x 4.19² / 9.8
= 0.150m x 17.5561 /9.8
= 0.2689
This is approximately 0.27
You want to draw a free body diagram of the forces on the sled in the horizontal x-direction.
If you visualize the system in an x-y coordinate plane, the force along the x-direction is the angle it makes with the x-axis multiples by the force.
The angle made with the x-axis is cosine of the angle theta.
Please see picture attached.
Answer:
140°
Explanation:
The law of reflection states that the angle of redlection equals to the angle of incidence.
When light rays hit surface at 20°, they also leave the surface at the same angle
Since the whole surface has 180° then subtracting these two angles from total angle gives the the angle between the incident and reflected rays.
180°-20°-20°=140°
The angle of incidence and reflection are equal hence 140/2=70°
The question needed the angle between the incident and reflected rays which is already calculated as 140°
Answer:
In any energy transformation, energy is the change of energy from one form to another.