A fuse is an electrical safety device which should not blow, which should overheat and melts if current is too high. Its placed in the live wire before the switch. This prevents overheating and catching fire. A fuse have a specific current value for example - 3000 amps. So when choosing a suitable fuse you must use the above minimum value but less than maximum value. For example in a circuit there is 1000W flowing, you should choose more than 1000 amps fuse not less or else, it will melt.
I beleive she isnt doing any work due to holding the box motionless, you must be exerting a force in the direction of the box motion. If she is just standing there holding the box their isn't no work becuase no distance has been covered. work = force = distance.
Question 18: a
question 19: b
question 20: c
Answer:
use hot water
Explanation:
hot water helps dissolve things faster
If the machine's mechanical advantage is 4.5, that means that
Output force = (4.5) x (Input force) .
We know the input force, and we need to find the output force. Rather than wander around the room looking at the floor while our hair smolders, let's try putting the numbers we know into the equation I wrote up there. OK ?
Output force = (4.5) x (Input force)
Output force = (4.5) x (800 N)
Now dooda multiplication:
<em>Output force = 3,600 N</em> .
That's exactly what the question asked for. So we're done !
