Answer: 4
The mechanical advantage is the ratio of the force exerted by the object to the force applied to do work on it.
Here, Jeff tried to lift a rock weighing 600 pounds by wedging board under the rock. Jeff who weighs 150 pounds uses all his weight to exert force on lever and lift rock.
Mechanical advantage, 
Therefore, the mechanical advantage that lever provided to Jeff in lifting rock is 4.
Answer: A
Explanation:
Isotopes of different elements differ by the number of neutrons inside the nucleus.
The answer is 2 because a and b are slowing it down by condensing it and then freezing it so its not one, b and c are opposites because b slows it down whereas c speeds it up so its not 3, and number 4 is the same explanation for number 3
hope you pass :)
Answer:
False?
Explanation:
Hope this helps you!
If this is wrong next time I will be better!
Answer:
Height above the floor from the bottom is 0.82m
Form the top is 1.71m
Explanation:
See attached file