Efficiency is calculated through dividing the actual mechanical advantage by the hypothetical mechanical advantage:
- the actual mechanical advantage is 9J because that's how much work the light bulb doing
- the hypo. mechanical advantage is 100J. Ideally, in a perfect world, the light bulb can convert 100J input into 100J output, but do to resistance and other factors it is not possible.

change the decimal to a percentage:

the light bulb had 9% efficiency
Answer:
cần cung cấp 70 độ vì nước sôi ở 100°C
Explanation:
In question 2
The second line of equation would be 54 = 108 + 10a
get the rest from that
Answer:
Fx = 22N
Explanation:
There are 2 possible scenarios for this problem:
1.- The 10N force is in the same direction of the acceleration. In this case the other force would be:
where F1 = 10N, m=6kg, a = 2m/s2
The negative result tells us that this is not possible.
2.- The 10N force is in the opposite direction of the acceleration. In this case the other force would be:

Because it is really hard and rocks can't be visible or vibrate