We have to calculate how many square feet a school custodian has to wax and to choose the correct answer. A gymnasium floor is in the shape of the square ( 20 by 20 feet ). The area of the square is : A = L^2. For L = 20 ft, A = 20^2 = 20 * 20 = 400 ft^2. Answer: <span>D. 400 square feet.</span>
Answer:
Volume of the sample: approximately
.
Average density of the sample: approximately
.
Assumption:
.
.- Volume of the cord is negligible.
Explanation:
<h3>Total volume of the sample</h3>
The size of the buoyant force is equal to
.
That's also equal to the weight (weight,
) of water that the object displaces. To find the mass of water displaced from its weight, divide weight with
.
.
Assume that the density of water is
. To the volume of water displaced from its mass, divide mass with density
.
.
Assume that the volume of the cord is negligible. Since the sample is fully-immersed in water, its volume should be the same as the volume of water it displaces.
.
<h3>Average Density of the sample</h3>
Average density is equal to mass over volume.
To find the mass of the sample from its weight, divide with
.
.
The volume of the sample is found in the previous part.
Divide mass with volume to find the average density.
.
Answer:
1.93 m/s
Explanation:
Parameters given:
Mass = 4.5g = 0.0045kg
Spring constant = 8.0 N/m
Length of barrel = 13 cm = 0.013m
Frictional force = 0.035N
Compression = 5.8 cm = 0.058m
First, we find the P. E. stored in the spring:
P. E. = ½*k*x²
P. E. = ½ * 8 * 0.058² = 0.013J
Then, we find the work done by the frictional force while the sphere is leaving the barrel of the gun:
Work = Force * distance
The distance here is the length of the barrel.
Work = 0.035 * 0.13 = 0.0046 J
The kinetic energy of the sphere can now be found:
K. E. = P. E. - Work done
K. E. = 0.013 - 0.0046 = 0.0084J
We can now find the speed using the formula for K. E.:
K. E. = ½*m*v²
0.0084 = ½ * 0.0045 * v²
v² = 0.0084/0.00255 = 3.733
=> v = 1.93 m/s
The answer to the question '<span>In a series of undisturbed rock layers where shale lies between sandstone below and limestone above, the __." would be limestone is youngest. Out of all the rock layers, the limestone is dated to be the youngest of all.</span>