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
Answer:

Explanation:
Given data
Speed v=2650 km/h
Radius r=85.0 km
To find
Centripetal Acceleration
Solution
As centripetal acceleration is given as

where
v is velocity
r is the radius
Substitute the given values in eq(i)

I am not sure the answers is correct
Magnetic Field, Magnetic Field, 1) When two magnets are brought near each other, like poles repel; opposite poles attract. ... We like to represent this force effect of a magnet on iron-like objects with a concept called magnetic field
The force (attractive if the charges are dissimilar, else repulsive) is along a line that connects the two particles.
The given figure shows the arrangement of vectors
-B is acting with a magnitude of 25 with 
So vector B is along the opposite direction of vector -B
Statement A is wrong since the direction is opposite
Statement B is also wrong since it makes 
Statement C is correct since it has 25 m magnitude
Statement D is wrong because vector's magnitude cannot be negative.
So option C is the correct answer.