Answer:
22m/s
Explanation:
To find the velocity we employ the equation of free fall: v²=u²+2gh
where u is initial velocity, g is acceleration due to gravity h is the height, v is the velocity the moment it hits the ground, taking the direction towards gravity as positive.
Substituting for the values in the question we get:
v²=2×9.8m/s²×25m
v²=490m²/s²
v=22.14m/s which can be approximated to 22m/s
<span>A. Comparison
</span>What type of organization is used in a paragraph that lists similarities between two objects? Comparison
NOT:
<span>B. Contrast
C. Chronological order
D. Cause and effect</span><span>
</span>
Answer:
"Scientist use radioactive decay to measure the age of a rock or fossil."
Explanation:
"To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events."
Answer:
Explanation:
According to Coulomb's law, the magnitude of the electric force between two point charges is directly proportional to the product of the magnitude of both charges and inversely proportional to the square of the distance that separates them:
Here k is the Coulomb constant. In this case, we have 
, 
and 
. Replacing the values:
The negative sign indicates that it is an attractive force. So, the magnitude of the electric force is:
