Answer:
c. nine times as low.
Explanation:
Sound intensity is defined as the acoustic power transferred by a sound wave per unit of normal area to the direction of propagation:
Since the sound wave has a spherical wavefront of radius r, then the area is given by:
Here r is the distance from the source of the sound. Thus sound intensity decreases as:
A silica-rich igneous rock that has large crystals and makes up much of the continental crust is called granite. These rocks are usually pink, gray or white in color depending on the minerals found on the rock. Generally, granite would have a range of 20% to 60% by volume of quartz and a minimum of 35% feldspar. This rock is a result from volcanic arcs and from the collision of continental masses. Due to its abundance, it has been used in a number of applications. It is used as an aggregate and filler in roading and construction industries. It is also cut and polished to be used in foyers, building facings, bench counters and tops.
Equatorial currents are primarily westward. This is because the dominant current in the northern hemisphere has a clockwise direction, while the southern hemisphere has a counterclockwise direction. When these two currents meet at the equator, a common westward current exists.
Answer:
Significant digits (also called significant figures or “sig figs” for short) indicate the precision of a measurement. A number with more significant digits is more precise. For example, 8.00 cm is more precise than 8.0 cm.
Answer:
A: The acceleration is 7.7 m/s up the inclined plane.
B: It will take the block 0.36 seconds to move 0.5 meters up along the inclined plane
Explanation:
Let us work with variables and set
As shown in the attached free body diagram, we choose our coordinates such that the x-axis is parallel to the inclined plane and the y-axis is perpendicular. We do this because it greatly simplifies our calculations.
Part A:
From the free body diagram we see that the total force along the x-axis is:
Now the force of friction is 
where 
is the normal force and from the diagram it is 
Thus 
Therefore,
Substituting the value for 
we get:
Now acceleration is simply
The negative sign indicates that the acceleration is directed up the incline.
Part B:
Which can be rearranged to solve for t:
Substitute the value of 
and 
and we get:
which is our answer.
Notice that in using the formula to calculate time we used the positive value of 
, because for this formula absolute value is needed.
