Answer:
a)q= 2800 W/m²
b)To=59.4°C
Explanation:
Given that
L = 10 mm
K= 20 W/m·K
T=30°C
h= 100 W/m²K
Ti=58°C
a)
Heat flux q
q= h ΔT
q= 100 x (58 - 30 )
q= 2800 W/m²
b)
As we know that heat transfer by Fourier law given as
Q= K A ΔT/L
Lets take outer temperature is To
So by Fourier law
To= Ti + qL/K
Now by putting the values
To= Ti + qL/K

To=59.4°C
Bridge freeze before road because of two reasons:
1. Bridge are exposed to environment from all sides. That is why they are more prone to temperature decrease. While roads are only exposed fro top, they are least prone to the environment as compare to bridges.
2. Bridge have more surface area for heat loss. While, road have lesser area available for heat loss.
Sources:
https://wonderopolis.org/wonder/why-do-bridges-freeze-before-roads
http://wxguys.ssec.wisc.edu/2011/02/28/why-do-bridges-ice-before-the-road/
http://icyroadsafety.com/icybridges.shtml
Explanation:
Higher amplitudes are associated with louder sounds. Higher amplitude means more energy while lower amplitude means lower energy. If the amplitude of wave is higher it will vibrate with higher energy. As energy of a wave is directly proportional to its intensity. So, higher amplitudes are associated with louder sounds.
Answer:
0.833 N
Explanation:
Formula for Kinetic Energy 
Formula for Potential Energy 
First we need to find the vertical distance between the maximum-angle position and the pendulum lowest point:
Using the swinging point as the reference, the vertical distance from the maximum-angle (34 degree) position to the swinging point is:

At the lowest position, pendulum is at string length to the swinging point, which is 1.2 m. Therefore, the vertical distance between the maximum-angle position and the pendulum lowest point would be
y = 1.2 - 1 = 0.2 m.
As the pendulum is traveling from the maximum-angle position to the lowest point position, its potential energy would be converted to the kinetic energy.
By law of energy conservation:




Substitute
and y = 0.2 m:

At lowest point, pendulum would generate centripetal tension force on the string:

We can substitute mass m = 0.25, rotation radius L = 1.2 m and v = 2 m/s:
