You can calculate potential energy by:
U = m.g.h
Where, U = potential energy
m = mass
g = acceleration due to gravity
h = height
Hope this helps!
Answer:
Explanation:
Even though the minimum temperature is more than the freezing point, Frost was observed on the ground because the ground will cool rapidly as cool air tends to move towards the ground, the temperature of the ground is lower than the atmosphere a few feet above it.
As the thermometer is kept some feet above the ground so ground temperature may be lower than the minimum recorded temperature.
Answer:
nm
Explanation:
= Index of refraction of soap bubble = 1.33
= thickness of the soap bubble = 115 nm = 115 x 10⁻⁹ m
= wavelength of light = ?
= order = 0
For reflection , the necessary condition is



nm
Answer:
<em>a. True</em>
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Explanation:
I'll assume the question is about magnetic latches and locks.
Magnetic door locks use an electromagnetic force to stop doors from opening, so they are ideal for security. There are two main types of electric locking devices. Locking devices can either be a fail-secure locking device that remains locked when power is lost, or a fail-safe locking device that is unlocked when de-energized. An electromagnetic lock creates a magnetic field when energized or powered up, this causes an electromagnet and armature plate to become attracted to each other strongly enough to keep a door from opening.
Answer:
U² = 142.86 N
U¹ = 357.14 N
Explanation:
Taking summation of the moment about point A, we get the following equilibrium equation: (taking clockwise direction as positive)

where,
W = weight of boy = 500 N
U² = reaction ay B = ?
Therefore,

<u>U² = 142.86 N</u>
Now, taking summation of forces on the plank. Taking upward direction as positive, for equilibrium position:

<u>U¹ = 357.14 N</u>