Answer:
a) the strong magnetic field inhibits the currents of hot gas rising from below.
Explanation:
Sunspots are dark because they are a little cooler than the photo sphere.
The magnetic field inhibits the strong rising currents of hot gas,allowing it to cool the surface.
Answer:0.253Joules
Explanation:
First, we will calculate the force required to stretch the string. According to Hooke's law, the force applied to an elastic material or string is directly proportional to its extension.
F = ke where;
F is the force
k is spring constant = 34N/m
e is the extension = 0.12m
F = 34× 0.12 = 4.08N
To get work done,
Work is said to be done if the force applied to an object cause the body to move a distance from its initial position.
Work done = Force × Distance
Since F = 4.08m, distance = 0.062m
Work done = 4.08 × 0.062
Work done = 0.253Joules
Therefore, work done to stretch the string to an additional 0.062 m distance is 0.253Joules
Answer:
(a) Energy density will be equal to 
(b) Total energy will be equal to 0.0718 J
Explanation:
It is given that length of solenoid l = 78.8 cm = 0.788 m
Cross sectional area 
Number of turns of the wire N = 914
Current in the solenoid i = 8.25 A
Inductance of the wire is equal to 
(b) Total energy stored in magnetic field 
(a) Energy density will be equal to
Acceleration = (velocity final-velocity initial)/ time
where
velocity final = 135 km/hr x 1 hr /3600 s x 1000m/1km
= 37.5 m/s
velocity initial = 35 km/hr x 1hr /3600 s x 1000 m/1 km
= 9.72 m/s
a) acceleration = 2.646 m/s^2
b) acceleration in g units = (2.646m/s^2)/(9.8m/s^2)
= 0.27 units
