Answer:
A. The box experiences more friction on the carpeted floor
Explanation:
Friction is the force that opposes the motion of an object when it slides along a surface. The magnitude of the friction is given by
where m is the mass of the object, g is the acceleration due to gravity, and 
is the coefficient of friction, which depends on the type of material of the surface: the larger this coefficient, the stronger the friction, the more difficult is to push the box along the surface. Generally, a smooth surface has a lower coefficient of friction, while a rough surface has a larger coefficient of friction.
In this case, Ethan find it easier to push the box on the marble floor, because marble is smoother than the carpet and so friction is weaker, while for the carpeted floor the coefficient of friction is larger and so the friction is stronger, making it more difficult to push the box.
Formula
F = k*x
Givens
F = 21 N
x = 13
K = ?
Solution
21 = 13 k
21/13 = k
k = 1.615 N / cm
The units are not quiet the ones you should be using. Newtons are found in the mks system.
13 cm [1 m / 100 cm ] = 0.13 m
So an alternate solution is
21 N = k * 0.13 m
k = 21 N / 0.13 m
k = 161.5 Newtons / meter. Answer
pshyical change is a usually reversible change of a substance, as size or shape: Freezing a liquid is a physical change. Compare chemical change.
internal change is when the movement of the particles increases
specific latent heat is the amount of energy per kg (unit mass) required to change ice to water without change in temperature.
Between the stars' absolute magnitudes<span> or </span>luminosities<span> versus their </span>stellar classifications<span> or </span>effective temperatures<span>. </span>
Answer:
Coal is fossil fuel extracted from earth and since it takes a long time to replenish, it is called a non renewable source of energy
Explanation:
Coal is formed from the fossil fuel that lie deep beneath the earth crust . These fossil fuels are dead remains of living organism that burried beneath the earth crust million of years ago.
Coal is non renewable because if once it gets depleted it will take a very very long time to replenish.
