Answer:
My answer is 7.2 km
Explanation:
When Stephen goes to the south and then to the east, he is drawing a right triangle, where the 4 km and 6 km sides are the cathetus of a right triangle.
Then we use the Pithagorean theorem to solve this problem. We need to find the hypotenuse.
c² = a² + b²
c² = 4² + 6²
c² = 16 + 36
c² = 52
c = 7.2 km
Answer:
A. a material burns out when current is excessive
Answer:
Zero
Explanation:
Given the equation of an ellipse:

The eccentrity of an ellipse is given by:

For a circle, we have

Therefore the eccentricity of a circle is

Answer:
Option B
Explanation:
Magnification of Microscope is

Mo= Magnification of objective lens and
Me= magnification of the eyepiece.
Both magnifications( of objective and eyepiece) are inversely proportional to the focal length.
Magnification,

when the focal length is less magnification will be high and when the magnification is the low focal length of the microscope will be more.
Thus. Magnification will increase by decreasing the focal length.
The correct answer is Option B i.e. using shorter focal length
Answer:
The initial and final temperatures of the gas is 300 K and 600 K.
Explanation:
Given that,
Entropy of the gas = 14.41 J/K
Absorb gas = 6236 J
We know that,

At constant pressure,



Put the value into the formula




...(I)
We need to calculate the initial and final temperatures of the gas
Using formula of energy

Put the value into the formula




Put the value of T₂


Put the value of T₁ in equation (I)


Hence, The initial and final temperatures of the gas is 300 K and 600 K.