Initially there were 10 bulbs of 60 Watt power
So total power of all bulbs = 60 * 10 = 600 W
now each bulb used for 4 hours daily
so total energy consumed daily



now we have total power consumed in 1 year

cost of electricity = 10 cents/ kWh
so total cost of energy for one year

Now if all 60 Watt bulbs are replaced by 30 Watt bulbs
So total power of all bulbs = 30 * 10 = 300 W
now each bulb used for 4 hours daily
so total energy consumed daily



now we have total power consumed in 1 year

cost of electricity = 10 cents/ kWh
so total cost of energy for one year

total money saved in 1 year

Answer:
7.68 m
Explanation:
Kinetic energy in ball = elastic energy in spring
KE = EE
½ mv² = ½ kx²
mv² = kx²
x = v √(m / k)
x = (38.5 m/s) √(20.5 kg / 515 N/m)
x = 7.68 m
Answer:
+5m/s
Explanation:
When doing the math we figure out that e is going to be slowing down at -4m/s² for 5 seconds. In total he is slowing down -20m/s which we take from the total speed of +25m/s to get his current new speed.
That would be false
Hope this helps :)