<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:
A
Explanation:
The energy of an electromagnetic wave is directly proportional to its frequency, according to the equation:
E = hf
where
h is the Planck constant
f is the frequency
The frequency of a wave is the number of complete cycles per unit of time: in the figures shown, we see that the more we go towards the right, the higher the frequency is (because the wavelength becomes shorter, so the waves makes more complete cycles per second). This means that the more the box is on the right, the higher the frequency: the figure with the box located more on the right is A, so this is also the figure that represents the range of frequencies with most energy.
Refer to the figure shown below.
W = 217/2 = 108.5 N, the weight of one half of the board.
N = W = 108.5 N, the normal reaction at B or C.
R = frictional force at B or C preventing the board from sliding.
The vertical dashed line through A is a line of symmetry.
By definition,
R = μN = 108.5μ N
where
μ = the static coefficient of friction between the board and the ground.
From geometry,
h = 2a tan(30°) = 1.1547a
Take moments about A for the member AB.
2aN - Rh -Wa = 0
2a(108.5) - 108.5μ(1.1547a) - 108.5 a = 0
217 - 125.285μ - 108.5 = 0
125.285μ = 108.5
μ = 0.866
This is the minimum required static coefficient of friction
Answer: 0.866
Answer
given,
mass of base ball = 0.14 kg
speed before it made the contact with the ball (V i) = 42 m/s
speed after batter hit the ball(V f) = - 48 m/s
a)
impulse = change in momentum
=
=
= -12.6 Kg m/s
Magnitude of impulse = 12.6 Kg m/s
b)
Force =
=
Force = 2520 N