Final answer:
To heat the gold bar from 25°C to 260°C, 1645 joules of heat are required. This calculates the total energy needed by multiplying the amount of energy per degree Celsius (7 joules) by the total change in temperature (235°C).
Step-by-step explanation:
The student is asking how many joules of heat would be needed to raise the temperature of a gold bar from 25 degrees Celsius to 260 degrees Celsius, given that it takes 7 joules to raise the temperature by 1 degree Celsius.
We can use the formula Q = mcΔT, where Q is the heat energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature. However, since we are not given the mass of the gold bar and we only need the heat required per degree, we can simplify the calculation by multiplying the energy per degree Celsius by the total change in temperature.
The change in temperature (ΔT) is the final temperature minus the initial temperature, which is 260°C - 25°C = 235°C. Since it requires 7 joules to raise the temperature of the bar by 1 degree Celsius, the total energy required will be 7 joules/degree Celsius * 235 degrees Celsius = 1645 joules.