PHYSICS HIGH SCHOOL

The principal limitation of wind power is unpredictability. Please select the best answer from the choices provideda. True
b. False

Answers

Answer 1
Answer: The correct answer is A: True. Although the ability to forecast weather has increased over the years, the ability to predict when and how much wind will occur at any given time and place is difficult. Weather conditions are subject to constant change and while some areas are known to have more wind than others, there is no guarantee about how much wind there will be as weather patterns vary in consistency.
Answer 2
Answer:

Answer:

A. True

Explanation:

Related Questions

Think back to what you learned about stress relief in this lesson. What stress-relief strategy works best for you? Why do you think it works best for you? In addition to what you listed above, which other activities (such as various aerobic exercises, yoga, or deep breathing) are, or might be, most helpful for you? Why do you think this is the case?
Enter the expression 2cos2(θ)−1, where θ is the lowercase Greek letter theta.
The half-life of carbon-14 is 5,730 years. How many grams of parent material will remain from a 120-gram sample of carbon-14 after 2 half-lives?
Which particle builds a static electric charge when it is transferred from one object to another? A.proton B.atom C.electron D.molecule
Part 1. A girl leaves a history classroom and walks 10 meters north to a drinking fountain. Then she turns and walks 30 meters south to an art classroom. What is the girl's total distance traveled? Part 2. Using the information above from Part 1. What is the girl's total displacement from the history classroom to the art classroom?

While John is traveling along an interstate highway, he notices a 194-mile marker as he passes through town. Later John passes another mile marker, 104. (a) What is the distance between town and John's current location? (b) What is John's current position?

Answers

Answer:

a) 90 miles is the distance between town and John's current location.

b) John's current position is the 104 mile marker.

Explanation:

See in the picture.

A ball is projected horizontally from the top of a 92.0-meter high cliff with an initial speed of 19.8 m/s. Determine: (a) the horizontal displacement and (b) the final speed the instant prior to hitting the ground.

Answers

Answer:

Part a)

d = 85.8 m

Part b)

v = 46.8 m/s

Explanation:

Part a)

As we know that ball is projected horizontally

so here the vertical speed of the ball is zero

now we have

y = (1)/(2)gt^2

now we have

92 = (1)/(2)(9.8)t^2

t = 4.33 s

now in the same time the horizontal distance covered by the ball

d = v_x t

d = 19.8 * 4.33

d = 85.8 m

Part b)

now the horizontal speed of the ball always remains constant

so we have

v_x = 19.8 m/s

now in vertical direction we have

v_y = v_0 + at

v_y = 0 + 9.8(4.33)

v_y = 42.4 m/s

so the final speed of the ball is given as

v = √(v_y^2 + v_x^2)

v = √(42.4^2 + 19.8^2)

v = 46.8 m/s
The ball has two independent motions; the vertical motion and the horizontal motion.
That is the ball is falling vertically downwards from the cliff and the same time the ball is moving horizontally forward from the cliff.
Note: Initial Vertical Speed is = 0, Initial Horizontal Speed = 19.8 m/s
For the vertical motion: the initial velocity is zero. That is u_(y) = 0.
S = (u_(y))t + (1/2)gt^2.                            where g = acceleration due to gravity = 10 m/s^2
S = Vertical height =  92m
Substituting u_(y) = 0, and  S = 92m, g = 10m/s^2
92 = 0*t  + (1/2)*10*t^2
92 = (1/2)*10*t^2
92 = 5t^2
5t^2 = 92
t^2 = 92/5
t^2 = 18.4    Take square root of both sides
t = √(18.4)
t = 4.29 seconds, that is the time to reach the ground. Time is same both for horizontal and vertical motion

a) Horizontal Displacement, which is Range R = Horizontal Speed * time
R = u_(x) * time
R = 19.8 * 4.29 = 84.942 m.

b) Final Speed before hitting the ground.
Remember we realized that speed was in two parts: Vertical Speed and Horizontal Speed.
Just before hitting the ground Horizontal speed is same = 19.8 m/s, this is the same as the initial horizontal projected speed. (No acceleration in Horizontal direction so this remains the same)
Just before hitting the ground, v_(y) = u_(y) + gt
At projection Vertical speed is initially zero  u_(y) = 0
v_(y) = 0 + 10*4.29  
Time is same both for horizontal and vertical motion
v_(y) = 42.9  m/s
The velocity just before hitting the ground is 19.8 m/s in the horizontal direction and 42.9 m/s in the vertical direction.
These two are at right angles to each other. Therefore the resultant is:
= \sqrt{19.8^(2)+ 42.9^(2) }
= 47.25 m/s.
This is the resultant velocity just before it hits the ground.

How much energy in joule does the heater deliver in 7 secondsThe heater has a power output of 3kW

Answers

Answer:

 J

A sound wave has a frequency of 425 Hz. What is the period of this wave?

Answers

period is 1/frequency
1/425 = 2.353ms

Two technicians are discussing hydraulics. Technician A says that if pistons of the same size are used, motion and force can be increased or decreased. Technician B says that if a small piston acts upon a larger piston, the force of the larger piston will increase, but the distance it travels will decrease. Who is correct? A. Technician B only B. Technician A only C. Both Technician A and B D. Neither Technician A nor B

Answers

the correct option is A. Only technician B is correct.

Hydraulics works on the pascal law, which states that in a direction the hydro static fluid pressure remains constant.

Px=Py=Pz

Since small piston has small area compare to the large piston

Pbig=Psmall

Fbig/Abig=Fsm/Asm

Fbig=(Abig)/(Asmall)*Fsmall

thus the force on the large piston will increase, but it travel small distance.

. Which of the following is not an ultimate goal of science?A. Understand patterns
B. Give explanations for natural events
C. Make predictions
D. Produce unchanging, absolute answers

Answers

What is not the ultimate goal of science is to produce unchanging and absolute answers - D. Scientists would like to, however, understand patterns, give explanations for natural events, and even make predictions. And it isn't really the case that they would like to produce unchanging answers.
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You are riding in a vehicle with a coffee cup on the dashboard while traveling 30 km/h. The vehicle makes a sudden stop to avoid hitting the car that hasstopped in front of it.