Answer:
I think no 3 is false
and 4 is true
and the the ones you did are correct
if wrong correct me pls
The point in which it originates.
Answer:
<em>The second option has a lower power output. P=30 W</em>
Explanation:
<u>Mechanical Power
</u>
It is a physical magnitude that measures the rate a work W is done over time t.

Since W=F.d

The first option means the worker will lift the box by a distance of 1.2 meters in 3 seconds by applying 250 N of force. That produces a power of

The second option requires the worker applies 75 N of force and travel a distance of 4 meters for 10 seconds, thus the power is

The second option has a lower power output
The first option.
The total mechanical energy before an action (which makes up PE and KE) equals the total mechanical energy after an action.
So
KEi + PEi = KEf + PEf