The answer I believe is c
Explanation
During the day when temperatures are higher, the snow melts and water enters the cracks in the rock. When the temperature drops below 0°C the water in the crack freezes and expands by about 9 per cent. This makes the crack larger.
<h2>
Answer: B. Gravitational potential energy </h2>
Explanation:
<em>The gravitational potential energy is the energy that a body or object possesses, due to its position in a gravitational field.
</em>
That is why this energy depends on the relative height of an object with respect to some point of reference and associated with the gravitational force.
In the case of the <u>Earth</u>, in which <u>the gravitational field is considered constant</u>, the value of the gravitational potential energy
will be:
Where
is the mass of the object,
the acceleration due gravity and
the height of the object.
As we can see, the value of
is directly proportional to the height.
Answer:
18.6012339739 A
Explanation:
= Vacuum permeability = 
L = Length of wire = 55 cm
N = Number of turns = 4000
I = Current
Magnetic field is given by

The current necessary to produce this field is 18.6012339739 A
Answer:
Force = 125 [N]
Explanation:
In the attached image we can see a sketch of the lever system.
And if we make a sum of moments at the point O equal to zero (0).
In the equation showed in the image, we can determinate the force that we need