A horizontal line on a speed/time graph means a constant speed.
Answer:

Explanation:
First of all let's define the specific molar heat capacity.
(1)
Where:
Q is the released heat by the system
n is the number of moles
ΔT is the difference of temperature of the system
Now, we can find n with the molar mass (M) the mass of the compound (m).
Using (1) we have:


I hope it helps!
Answer:

Explanation:
Static friction occurs when an object initially starts at rest. When the surfaces of the materials touch, the microscopic unevenness interlock greatest with each other, causing the most friction out of the three.
During sliding friction, an object is already moving or in motion. The microscopic surfaces still interlock, but because the object is in motion, it has a momentum. Therefore, the magnitude of sliding friction is less than that of static friction.
Rolling friction occurs when an object rolls across some surface. Rather than surfaces interlocking, rolling friction is caused by the constant distortion of surfaces. As it rolls, the surfaces of the object are constantly wrapping and changing. This distortion causes the rolling friction. However, it is much less in magnitude when compared to static or sliding friction.
Answer:
El punto de referencia más usado es el NORTE. Los puntos de referencia sirven para orientarnos, de esta manera podemos saber nuestra ubicación y luego desplazarnos. En este caso tenemos que el punto cardinal NORTE es el más usado, se tiene como referencia universal para lograr ubicarnos.
Explanation:
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