You may confuse two minerals by their colors so using streak is another way for showing their "true colors "
Friction is causing the skateboard to stop rolling.
Answer: <span>D. A bimetallic strip bends so that the steel is on the outside curve
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When something has an increased temperature, its volume will expand. Then, if the temperature drops, its volume should be smaller. From there option A and B are out since the liquid in thermometer is expand or move up.
When you put two kinds of different metal with a different coefficient of thermal expansion, the outer curve metal will be the one with lesser coefficient when temperature drop. Since the question about drop in temperature then the metal should be bend
Brass will expand 1.5 times more than the steel so the outer curve would be the steel.
Answer with Explanation:
The force of attraction between 2 charges of magnitude
separated by a distance 'r' is given by
where
is a constant known as permitivity of free space

Applying the given values in the above relation we get

The velocity is 4374.45 m/s.
I got the answer by using v=d/t.
20,000meters / 25min= 4,374.45 m/s.