We can't tell without more information. We know it will be higher than 40 and lower than 75, but we don't know exactly where it will settle. In order to work that out, we would need to know the volumes of the water and the cube, and WHAT metal the cube is made of.
Speed is the rate of distance traveled per unit of time without regards to direction.
<u>Explanation</u>:
Speed is the pace of separation traveled per unit of time, regardless of direction.
Speed is straightforwardly relative to separate when time is consistent and conversely corresponding to a time when separation is steady. Multiplying one's speed would mean multiplying one's separation went in a given measure of time. Multiplying one's speed would likewise mean splitting the time required to travel a given separation.
Answer:
Total energy saving will be 0.8 KWH
Explanation:
We have given there are 50 long light bulbs of power 100 W so total power of 50 bulb = 100×50 = 5000 W = 5 KW
30 bulbs are of power 60 W
So total power of 30 bulbs = 30×60 = 1800 W = 1.8 KW
Total power of 80 bulbs = 1.8+5 = 6.8 KW
Total time = 3 hour
We know that energy 
Now power of each CFL bulb = 25 W
So power of 80 bulbs = 80×25 = 2000 W = 2 KW
Energy of 80 bulbs = 2×3 = 6 KWH
So total energy saving = 6.8-6 = 0.8 KWH