Answer: 216.2 J
Explanation: The heat energy of copper is the expressed in Q=mc∆T. First make sure that the mass 0.0693 kg is converted into grams to cancel both units.
Q= 69.3 g x 390 J/g°C x 26 °C-18°C = 216.2J
Answer:
x coordinate = -1.66 m
y coordinate is = -0.825m
Explanation:
Suppose z be the distance form the first charge and z + sqrt(1^2 +.5^2) be the distance from the second So z + sqrt(1+.25) = z + 1.12
We have k*2.0x10^-6/s^2 = k*6x10^-6/(s+1.12)^2
0.0356s^2 -0.019s-0.0897=0
s=1.876m
The angle of the line between the two charges is arctan(.5/1) = 26.6o
x coordinate = -1.876*cos(26.6) = -1.66m
y coordinate is -1.876*sin(26.6) = -0.825m
The frequency, the speed and the wavelength of a wave are related by the following equation:

(1)
where
f is the frequency

is the wavelength
v is the wave speed
The speed of the wave does depend only on the properties of the medium, so since the wave is still traveling in air, the medium has not changed and therefore the speed remains the same. We see instead from eq.(1) that the frequency is inversely proportional to the wavelength, so if the wavelength is decreased by half, we see that the frequency will double.
Answer: Photoelectric effect
Explanation:
Momentum = Mass × Velocity
= 61 × 8
= 488 kg m/s east
= 500 kg m/s east
Momentum is a vector quantity which means it has a direction as well as a numerical value (fancy word for this is magnitude). This means the final answer should also be in the direction "east".
Furthermore due to the significant figures in the question, the final answer should also be given to 1 sig fig (500) but if you don't want to then I imagine 488 is acceptable. (It's like this because we don't know how accurate we can be with the final answer from the numbers in the question.)