Answer:
Power, 
No of bulbs = 78400000
Explanation:
We have,
Water flows over Niagara Falls at the average rate of 2,400,000 kg/s, it mean it is mass per unit time i.e. m/t.
It falls from a height of 50 m
The gravitational potential energy of falling water is given by :
P = mgh
Power is equal to the work done divided by time taken. So,
So,
Let there are n bulbs that could power 15 W LED. It can be calculated by dividing the power by 15. So,
It means that the number of bulbs are 78400000.
Answer:
Explanation
Comment
Normally you would just use m*c*delta T. But the c is the same in both cases, so you need just use m*deltaT
Givens
25 degrees
m = ?
T = 25
t = final temp = 75
93 degrees
m = 250
T = 93
t = final temp = 75
Solution
(t - 25)*m = (93 - t) * 250 Remove the brackets
75*m - 25m = 93*250 - 250*75 Combine the right
m(75 - 25) = 23250 - 250*75
50 m = 23250 - 18750 Combine
50 m = 4500 Divide both sides by 50
50*m/50 = 4500/50
m = 90
Answer: 90 grams are needed.
The average speed of the family : 70 km/h
<h3>Further explanation</h3>
Given
time = 2 hour
distance = 140 km
Required
The average speed
Solution
Distance is the length traveled by an object within a certain time
Average speed = total distance/total amount of time
Can be formulated :
Avg speed = d : t
Total distance traveled : 140 km
Total time : 2 hr
Avg speed = 140 : 2 = 70 km/h
