Answer:
630.75 j
Explanation:
from the question we have the following
total mass (m) = 54.5 kg
initial speed (Vi) = 1.4 m/s
final speed (Vf) = 6.6 m/s
frictional force (FF) = 41 N
height of slope (h) = 2.1 m
length of slope (d) = 12.4 m
acceleration due to gravity (g) = 9.8 m/s^2
work done (wd) = ?
- we can calculate the work done by the boy in pushing the chair using the law of law of conservation of energy
wd + mgh = (0.5 mVf^2) - (0.5 mVi^2) + (FF x d)
wd = (0.5 mVf^2) - (0.5 mVi^2) + (FF x d) - (mgh)
where wd = work done
m = mass
h = height
g = acceleration due to gravity
FF = frictional force
d = distance
Vf and Vi = final and initial velocity
wd = (0.5 x 54.5 x 6.9^2) - (0.5 x 54.5 x 1.4^2) + (41 x 12.4) - (54.5 X 9.8 X 2.1)
wd = 630.75 j
By Snell's law:
η = sini / sinr. i = 25, η = 1.33
1.33 = sin25° / sinr
sinr = sin25° / 1.33 = 0.4226/1.33 = 0.3177 Use a calculator.
r = sin⁻¹(0.3177)
r ≈ 18.52°
Option A.
God's grace.
Answer:
Yes it would be different on Earth and the moon
<h3>Hello there!</h3>
Here, you are looking for the amount of heat put in for water, at a mass of 187 grams, to change by 80 degrees.
The equation commonly accepted to find the answer to questions like these is the specific heat formula.
The equation is Q = mc∆T, where Q is the amount of energy put in to raise the temperature by a certain amount, m is the mass, c is the specific heat capacity, and ΔT is the amount of temperature change.
The information given:
m = 187 grams
c = specific heat capacity of water, or in this case 1 calorie, or 4.184 joules (which is what we will be using)
ΔT = 80 degrees
Now just plug everything in to solve.
Q = 187 * 4.184 * 80
Q = 62592.64
So you have your answer: 62592.64 joules.
Hope this helped!
Answer:
A.
Explanation:
Earth is composed of different layers and one layer moves over another due to differences in the densities.
According to the physics of density, a substance having less density floats over a higher density substance. The oceanic crust has more density than the continental crust that is why continental crust float over oceanic crust.
So in the given example, plate B is moving below the plate A, it means plate B is more dense than plate A because plate B is composed of oceanic crust
. <u>For example : continents float over the asthenosphere (a layer below the lithosphere).</u>
Hence, the correct answer is "A
".
