42- C
43- A
44- C
45- A
46- B
47- D
Answer:
a) The perimeter of the rectangle is 29.4 centimeters.
b) The uncertainty in its perimeter is 0.8 centimeters.
Explanation:
a) From Geometry we remember that the perimeter of the rectangle (
), measured in centimeters, is represented by the following formula:
(1)
Where:
- Width, measured in centimeters.
- Length, measured in centimeters.
If we know that 
and 
, then the perimeter of the rectangle is:
The perimeter of the rectangle is 29.4 centimeters.
b) The uncertainty of the perimeter (
), measured in centimeters, is estimated by differences. That is:
(2)
Where:
- Uncertainty in width, measured in centimeters.
- Uncertainty in length, measured in centimeters.
If we know that 
and 
, then the uncertainty in perimeter is:
The uncertainty in its perimeter is 0.8 centimeters.
Answer: 40.2 hp
Explanation:
The mass of the car is 2000kg.
in 21 seconds, it accelerates from 0m/s to 25m/s, so the average acceleration is:
a = (25m/s)/(21s) = 1.2 m/s^2
We know that force = mass*acceleration, then:
F = 2000kg*1.2m/s^2 = 2400N.
Now, the Power can be written as:
P = W/t where W is work = F*d (force per distance) and t is time.
then we have:
P = (F*d)/t and d/t is the average velocity, and we know the velocity v = 25m/s, so the average velocity will be (1/2)*25m/s = 12.5m/s
P = F*12.5m/s
and the force is F = 2400N
P = 2400 N*12.5m/s = 30,000 W
and we know that 1hp = 746 W
then, P = (30,000/746) hp = 40.2 hp
Answer:
The electric field strength is 
Solution:
As per the question:
Area of the electrode, 
Charge, q = 50 nC = ![50\times 10^{- 9} C[/etx]Distance, x = 2 mm = [tex]2\times 10^{- 3} m](https://tex.z-dn.net/?f=50%5Ctimes%2010%5E%7B-%209%7D%20C%5B%2Fetx%5D%3C%2Fp%3E%3Cp%3EDistance%2C%20x%20%3D%202%20mm%20%3D%20%5Btex%5D2%5Ctimes%2010%5E%7B-%203%7D%20m)
Now,
To calculate the electric field strength, we first calculate the surface charge density which is given by:
Now, the electric field strength of the electrode is:
where
