Answer:
<h3>The answer is option B</h3>Explanation:
The frequency of a wave can be found by using the formula
where
c is the velocity
From the question
wavelength = 0.39 m
c = 86 m/s
We have
We have the final answer as
<h3>200 Hz</h3>Hope this helps you
Answer:
80.4 N
Explanation:
As the block is at rest on the slope, it means that all the forces acting on it are balanced.
We are only interested in the forces that act on the block along the direction perpendicular to the slope. Along this direction, we have two forces acting on the block:
- The normal reaction N (contact force), upward
- The component of the weight of the block, , downward, where m is the mass of the block, g is the gravitational acceleration and
is the angle of the incline
Since the block is in equilibrium along this direction, the two forces must balance each other, so they must be equal in magnitude:
And by substituting the numbers into the equation, we find the size of the contact force normal to the slope: