Answer:
1 st question: Control variable
2nd question: random variable
3rd question: if the two objects are dropped from the same height they will hit the ground at the same time
Answer:
Length of Eiffel tower, when the temperature is 35 degrees = 300.21 m
Explanation:
Thermal expansion is given by the expression

Here length of Eiffel tower, L = 300 m
Coefficient of thermal expansion, α = 0.000012 per degree Celsius
Change in temperature, = 35 - (-24) = 59degrees Celsius
Substituting

Length of Eiffel tower, when the temperature is 35 degrees = 300 + 0.2124 = 300.21 m
Answer:

Explanation:
We have,
Mass of Mars is, 
Mass of its moon Phobos, 
Distance between Mars and Phobos, d = 9378 km
It is required to find the gravitational force between Mars and Phobos. The force between two masses is given by

Plugging all values, we get :

So, the gravitational force is
.
Answer:
Thomas Edisons most famous invention was the phonograph
Thomas Edison announces his invention of the phonograph, a way to record and play back sound. Edison stumbled on one of his great inventions—the phonograph—while working on a way to record telephone communication at his laboratory in Menlo Park, New Jersey.
Explanation:
Hope I helped
Answer: 4.9 x 10^6 joules
Explanation:
Given that:
mass of boulder (m) = 2,500 kg
Height of ledge above canyon floor (h) = 200 m
Gravita-tional potential energy of the boulder (GPE) = ?
Since potential energy is the energy possessed by a body at rest, and it depends on the mass of the object (m), gravitational acceleration (g), and height (h).
GPE = mgh
GPE = 2500kg x 9.8m/s2 x 200m
GPE = 4900000J
Place result in standard form
GPE = 4.9 x 10^6J
Thus, the gravita-tional potential energy of the boulder-Earth system relative to the canyon floor is 4.9 x 10^6 joules