Answer:
The answer is A Ruler and Balance
Explanation:
Answer: All of our energy comes from the sun, which is our nearest star. The sun sends out huge amounts of energy through its rays every day. We call this energy solar energy or radiant energy. Without the sun, life on earth would not exist, since our planet would be totally frozen.
Answer:
<em>1.43 s.</em>
Explanation:
Using one of the equations of motion,
S = ut + 1/2gt².......................... Equation 1
Where S = height of the cliff, u = initial velocity, t = time, g = acceleration due to gravity.
<em>Note: When the rock begins to fall from the maximum height, u = 0 m/s, g = positive</em>
<em>Given: S = 10 m, u = 0 m/s</em>
<em>Constant: g = 9.8 m/s²</em>
<em>Substituting these values into equation,</em>
<em>10 = 0(t) + 1/2(9.8)(t²)</em>
<em>10 = 0 + 4.9t²</em>
<em>t² = 10/4.9</em>
<em>t² = 100/49</em>
<em>t = √(100/49)</em>
<em>t = 10/7</em>
<em>t = 1.43 s.</em>
<em>Thus the rock spend 1.43 s in air</em>
