Answer:
The boat is 192 feet from the cliff.
Explanation:
Hi there!
Please see the attached figure for a graphical description of the problem.
Notice that the line of sight, the distance to the cliff and the height to the top of the lighthouse form a right triangle. Hence, we can apply trigonometric rules to find the distance from the boat to the cliff:
cos 20° = adjacent side / hypotenuse
sin 20° = opposite side / hypotenuse
The length of the opposite side is the height of the cliff plus the height of the lighthouse:
opposite side = 45 feet + 25 feet = 70 feet.
Using the equation of sin 20°, we can obtain the hypotneuse:
sin 20° = opposite side / hypotenuse
hypotenuse · sin 20° = opposite side
hypotenuse = opposite side / sin 20°
hypotenuse = 70 feet / sin 20°
hypotenuse = 205 feet
Now, using the equation of cos 20°, we can calculate the distance to the cliff (the length of the adjacent side):
cos 20° = adjacent side / hypotenuse
hypotenuse · cos 20° = adjacent side
205 feet · cos 20° = adjacent side
adjacent side = 192 feet (without rounding intermediate results)
The boat is 192 feet from the cliff.
Answer:
192 ft.
Explanation:
Tan (20) = Opp/Adj
Tan (20) = (45+25)/x
Tan (20) = 70/x
then x=70/Tan (20)
x= 192.3234 ft, and then rounded to the nearest foot...
x= 192 ft
B. Sample A would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the largest.
C. Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
D. Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the largest.
Answer: Option C: Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
Explanation:
The absorption coefficient of the samples is given. Sample A has 30%, Sample B has 47% and Sample C has 62%. This means that sample C absorbs the most percentage of energy incident on it. The energy in the reflected wave would be least. Hence, it would be best to use for a room to make it soundproof.
The correct answer is Option C) Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
As the coefficient of absorption would define the energy present in the reflected wave, the material C has the highest percentage of absorption i.e. 62% and would be best suitable to make a sound proof room.
b. velocity
c. time
d. acceleration
Answer:
a) 4.00 rad/s
b) 0.6 m/s, 0.3 m/s²
Explanation:
Given:
ω₀ = 0 rad/s
α = 2.00 rad/s²
t = 2.00 s
Find:
a) ω
b) v, a
a) ω = αt + ω₀
ω = (2.00 rad/s²) (2.00 s) + (0 rad/s)
ω = 4.00 rad/s
b) v = ωr
v = (4.00 rad/s) (0.15 m)
v = 0.6 m/s
a = αr
a = (2.00 rad/s²) (0.15 m)
a = 0.3 m/s²
Inertia is determined by the mass of the object. greater the mass an object has, greater will be its inertia. smaller the mass an object has, smaller will be its inertia. Greater mass enables an object to resist change in its state of motion or rest while on the other hand smaller mass object can be easily made to change its state of motion or rest.
Answer:
A brush is a device which conducts current between stationary wires and moving parts, most commonly in a rotating shaft.