Answer:
Explanation:
Total heat gain by the block ΔQ = 2 x 12 kJ = 24 kJ .
Gain of potential energy = mgh = 12 x 9.8 x 32 = 3.763 kJ
Decrease in kinetic energy KE = 1/2 x 12 ( 40² - 7² )
= 9.306 kJ
increase in internal energy ΔE = 70 kJ
ΔQ = ΔE + PE - KE + W , W is work done by the gas
Putting the values
24 = 70 + 3.763 - 9.306 + W
W = - 40.457 kJ .
Since W is negative that means work is done on the system .
Go to take picture and post it so I can see the choices for the question it will be more easy for us to answer
W = F x d/x = (m x Ag) x h, therefore, mass (2kg x 9.8) x 2.5m = 49J
Answer:
the sound intensity at the position of the microphone is 7.4 × 10⁻⁴ W/m²
Explanation:
Given the data in the question;
Sound power P = 26.0 W
Area of microphone A = 1.00 cm²
Radius r = 53.0 m
sound intensity at the position of the microphone = ?
Now, intensity at the position of the microphone can be determined using the following expression;
= P / 4πr²
We substitute
= 26.0 / ( 4 × π × (53.0 )² )
= 26.0 / ( 4 × π × 2809 )
= 26.0 / 35298.935
= 26.0 / ( 4 × π × (53.0 )² )
= 0.000736566
= 7.4 × 10⁻⁴ W/m²
Therefore, the sound intensity at the position of the microphone is 7.4 × 10⁻⁴ W/m²