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.
2.5m/s
Explanation:
Given parameters:
Initial velocity = 0m/s
Acceleration = 0.5m/s²
time of travel = 5s
Solution:
Final velocity = ?
Solution:
Acceleration can be defined as the change in velocity with time:
Acceleration = 
From the equation above, the unknown is final velocity:
Final velocity - initial velocity = Acceleration x time
since initial velocity = 0
Final velocity = 0.5 x 5 = 2.5m/s
Learn more:
Acceleration brainly.com/question/3820012
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Answer:
Yes, the calorie can be expressed in SI units
Explanation:
1 calorie (1 cal) is defined as the amount of heat energy that must be supplied to 1 gram of water in order to raise its temperature by 1 degree Celsius (
.
The calorie is not a unit of the International System (SI): the SI unit for the energy is the Joule (J).
However, it is possible to convert energy from calories to Joules, and viceversa. In fact, the conversion factor between the two units is:
1 calorie = 4.184 Joules
So, to convert from calories to Joules we simply multiply by 4.184, while if we want to convert from Joules to calories, we just divide by 4.184.
Answer: this isnt really helping me
Explanation: