Answer:120 min
Explanation:
Given
Amanda spent
of her time after school doing Home work
And
of her remaining time riding her bike
It is given that she rode her bike for 45 minutes in a week
Let t be the time after school
therefore Amanda spend
in home work and
time is left
From remaining
time she spends
time riding her bike
therefore 
thus 
therefore time spent on home work is 
Answer:
Q = 2.95*10^5 kJ
Explanation:
In order to calculate the energy required to melt the cooper, you first calculate the energy required to reach the boiling temperature. You use the following formula:
(1)
m: mass of cooper = 540 kg
c: specific heat of cooper = 390 J/kg°C
Tb: boiling temperature of cooper = 1080°C
T1: initial temperature of cooper = 20°C
You replace the values of the parameters in the equation (1):

Next, you calculate the energy required to melt the cooper by using the following formula:
(2)
Lf: melting constant of cooper = 134000J/kg

Finally, the total amount of energy required to melt the cooper from a temperature of 20°C is the sum of Q1 and Q2:

The total energy required is 2.95*10^5 kJ