Answer:
a. 12.57 m/s b. 39.5 m/s² c. Her centripetal force is four times her weight.
Explanation:
a. What is Missy's linear speed on the rotor?
Missy's linear speed v = 2πr/T where r = radius = 4.0 m and T = time it takes to complete one revolution = 2.0 s
So, v = 2πr/T
= 2π(4.0 m)/2.0 s
= 4π m/s
= 12.57 m/s
b. What is Missy's centripetal acceleration on the rotor?
Missy's centripetal acceleration, a = v²/r where v = linear velocity = 12.57 m/s and r = radius = 4.0 m
a = v²/r
= (12.57 m/s)²/4.0 m
= 158.01 m²/s² ÷ 4.0 m
= 39.5 m/s²
c. If her mass is 50-Kg, how is the centripetal force compare to her weight?
Her centripetal force F = ma where m = mass = 50 kg and a = centripetal acceleration = 39.5 m/s².
Her weight W = mg where m = mass = 50 kg and g = acceleration due to gravity = 9.8 m/s².
So, comparing her centripetal force to her weight, we have
F/W = ma/mg
= a/g
= 39.5 m/s² ÷ 9.8 m/s²
= 4.03
≅ 4
So her centripetal force is four times her weight.
Answer:
The average power delivered by the elevator motor during this period is 6.686 kW.
Explanation:
Given;
mass of the elevator, m = 636 kg
initial speed of the elevator, u = 0
time of motion, t = 4.5 s
final speed of the elevator, v = 2.05 m/s
The upward force of the elevator is calculated as;
F = m(a + g)
where;
m is mass of the elevator
a is the constant acceleration of the elevator
g is acceleration due to gravity = 9.8 m/s²

F = (636)(0.456 + 9.8)
F = (636)(10.256)
F = 6522.816 N
The average power delivered by the elevator is calculated as;

Therefore, the average power delivered by the elevator motor during this period is 6.686 kW.
Answer:
A.The positive z-direction
Explanation:
We are given that
Linear charge density of long line which is located on the x-axis=
Linear charge density of another long line which is located on the y-axis=
We have to find the direction of electric field at z=a on the positive z-axis if
and
are positive.
The direction of electric field at z=a on the positive z-axis is positive z-direction .
Because
and
are positive and the electric field is applied away from the positive charge.
Hence, option A is true.
A.The positive z-direction
The answer I believe is c
Explanation
During the day when temperatures are higher, the snow melts and water enters the cracks in the rock. When the temperature drops below 0°C the water in the crack freezes and expands by about 9 per cent. This makes the crack larger.