Answer:
2.03 Ω
Explanation:
EMF: This can be defined as the potential difference of a cell when it is not delivering any current. The S.I unit of Emf is Volt.
The formula of emf is given as,
E = I(R+r)............................ Equation 1
Where E = Emf, I = current, R = External resistance, r = internal resistance.
Make r the subject of the equation
r = (E-IR)/I........................ Equation 2
Note: From ohm's law, V = IR.
r = (E-V)/I........................ Equation 3
Where V = Terminal voltage
Given: E = 24 V, I = 3.9 A, V = 16.1 V.
Substitute into equation 3
r = (24-16.1)/3.9
r = 7.9/3.9
r = 2.03 Ω
Answer:
She must stop the car before interception, distance traveled 12.66 m
Explanation:
We will take all units to the SI system
Vo = 48Km / h (1000m / 1Km) (1h / 3600s) = 13.33 m / s
V2 = 70 Km / h = 19.44 m / s
We calculate the distance traveled before stopping
X = Vo t + ½ to t²
Time is what it takes traffic light to turn red is t = 2.0 s
X = 13.33 2 + 1.2 (-7) 2²
X = 12.66 m
It stops car before reaching the traffic light turning to red
Let's analyze what happens if you accelerate, let's calculate the acceleration of the vehicle
V2 = Vo + a t2
a = (V2-Vo) / t2
a = (19.44-13.33) /6.6
a = 0.926 m / s2
This is the acceleration to try to pass the interception, now let's calculate the distance it travels in the time the traffic light changes from yellow to red (t = 2.0 s)
X = Vo t + ½ to t²
X = 13.33 2 + ½ 0.926 2²
X = 28.58 m
Since the vehicle was 30 m away, the interception does not happen
Answer:
Calcium chloride in an ionic compound. The calcium atom loses two electrons, and each chlorine atom gains one electron, to form a full outer shell of electrons.
Answer:
FALSE
Explanation:
Velocity = speed with direction.
Think of speed and direction like rockets and missiles. Rockets are not smart. Missiles are smart. Rockets go in one direction. Missiles can track their targets, they have a specific destination, a specific direction.
Velocity is often used in physics, because its almost useless to know how fast an object is going if you don't know which direction it is going.
Think of it like this. If the Weather man told you a hurricane was traveling at 30 miles an hour, but didn't tell you which direction it was going, you would have no idea where to run, or if it was going to hit you at all. However, if he told you it was going 30 miles an hour to the North, and you were West of it, you would be fine, and wouldn't have to worry.
