Work = force * distance.
<span>You must produce twice as much energy as we are lifting the weight twice as high. </span>
<span>But because you aren't increasing the force, you need to increase the length of the ramp instead. </span>
<span>The new length will be twice as great as the previous length. </span>
<span>So 8 metres is required. </span>
Hope this helps.
The two possible angles obtained by using the qudratic equation are;
θ
= 15.10° and θ2 = 73.51°
Given, speed of water =
= 50ft/s
For the motion along x direction, time period can be calculated as follows:

35 = (50 × cosθ) t
t = 0.64 / cosθ
For the motion in y direction, an equation can be obtained as follows:


θ) 
Plugging in the values we get:

θ) 
-20 = -32tanθ - 10.304
θ
Upon solving the above quadratic equation, we get,
tanθ = 0.27 , -3.38
Therefore,
tanθ
= 0.27
θ
= 15.10°
and, tanθ
= -3.38
θ
= 73.51
Learn more about quadratic equation here:
brainly.com/question/17177510
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Explanation:
Given that,
Force with which a child hits a ball is 350 N
Time of contact is 0.12 s
We need to find the impulse received by the ball. The impulse delivered is given by :

So, the impulse is 42 N-m..
We know that he change in momentum is also equal to the impulse delivered.
So, impulse = 42 N-m and change in momentum =42 N-m.
Before a person walks through burning coal, the person will make sure their feet are very wet. When they start walking on the coal, this moisture will evaporate and form a protective gas layer underneath the person's feet. You can see examples of this if you happen to drip some water on a hot stove or any very hot surface. The water will very easily glide around on top of a newly formed layer of air underneath it -- like air hockey pucks on an air hockey table. Note that when someone walks through burning coal, typically this is also done very quickly to prevent a great deal of exposure to possible harm. By walking quickly, thinking positively, and letting the water cushion you from immediate danger over a short distance, such a task is possible. You may have also heard of physics teachers demonstrating how this principle works by sticking their hand first in a bucket of water and then quickly in a bucket of boiling molten lead. In the lead, their hand is protected briefly by a layer of gas from the evaporated water (the water vapor). I'm fairly sure that there is a name for this particular layer of gas, but I'm afraid the name is beyond me at the moment. In other words, water vapor has a low heat capacity and poor thermal conduction. Very often, the coals or wood embers that are used in fire walking also have a low heat capacity. Sweat produced on the bottom of people's feet also helps form a protective water vapor. All of this together makes it possible, if moving quickly enough, to walk across hot coals without getting burned. WARNING: Do not attempt to perform any of the actions described above. You can seriously injure yourself. Answered by: Ted Pavlic, Electrical Engineering Undergrad Student, Ohio St. (citing my source)
This could be Hubble's law, or something related to it. I think there's a possibly Doppler RED SHIFT in the optical spectra of stars etc as observed on the earth. It seems that they are accelerating away from the earth, and that the further away they are the faster they are moving.
It seems that this has been connected to the idea of "The Big Bang" theory of the origin of the universe which seems to have superceded Professor Sir Fred Hoye's Steady State theory of the universe.
There's some Special Relativity in this lot, too.