Answer:
a) t = 0.74s
b) D = 4.76m
c) Vf = 5.35m/s
Explanation:
The ball starts rolling when Vf = ωf*R.
We know that:
Vf = Vo - a*t
ωf = ωo + α*t
With a sum of forces on the ball:




With a sum of torque on the ball:



Replacing both accelerations:


t=0.74s
The distance will be:


Final velocity:

Vf=5.35m/s
Answer:
a) force between them is attraction, b) F = 1.125 10⁻² N
Explanation:
In this case the electric force is given by Coulomb's law
F =
In the exercise they give us the values of the loads
q1 = - 10 mC = -10 10⁻³ C
q2 = 5 mC = 5 10⁻³ C
d = 20 cm = 0.20 m
let's calculate
F = 9 10⁹
F = 1.125 10⁻² N
To find the direction of the force we use that charges of the same sign repel each other, as in this case there is a positive and a negative charge, the force between them is attraction
Answer: 0.392 m/s
Explanation:
The Doppler shift equation is:

Where:
is the actual frequency of the sound wave
is the "observed" frequency
is the speed of sound
is the velocity of the observer, which is stationary
is the velocity of the source, which are the red blood cells
Isolating
:


Finally:

The voltage in the extension cord is 30 V.
The problem above can be solved using ohm's law
⇒ Formula:
V = IR.................. Equation 1
⇒ Where:
- V = Voltage in the extension cord
- I = Current flowing through the extension cord
- R = Resistance of the extension cord.
From the question, I think there was a slight error in the value of the current given it suppose to be 500 A, and not 5.00 A
⇒ Given:
⇒ Substitute these values into equation 1
Hence the voltage in the extension cord is 30 V
Learn more about voltage here: brainly.com/question/4429782