John weighs 200 pounds.
In order to lift himself up to a higher place, he has to exert force of 200 lbs.
The stairs to the balcony are 20-ft high.
In order to lift himself to the balcony, John has to do
(20 ft) x (200 pounds) = 4,000 foot-pounds of work.
If he does it in 6.2 seconds, his RATE of doing work is
(4,000 foot-pounds) / (6.2 seconds) = 645.2 foot-pounds per second.
The rate of doing work is called "power".
(If we were working in the metric system (with SI units),
the force would be in "newtons", the distance would be in "meters",
1 newton-meter of work would be 1 "joule" of work, and
1 joule of work per second would be 1 "watt".
Too bad we're not working with metric units.)
So back to our problem.
John has to do 4,000 foot-pounds of work to lift himself up to the balcony,
and he's able to do it at the rate of 645.2 foot-pounds per second.
Well, 550 foot-pounds per second is called 1 "horsepower".
So as John runs up the steps to the balcony, he's doing the work
at the rate of
(645.2 foot-pounds/second) / (550 ft-lbs/sec per HP)
= 1.173 Horsepower. GO JOHN !
(I'll betcha he needs a shower after he does THAT 3 times.)
_______________________________________________
Oh my gosh ! Look at #26 ! There are the metric units I was talking about.
Do you need #26 ?
I'll give you the answers, but I won't go through the explanation,
because I'm doing all this for only 5 points.
a). 5
b). 750 Joules
c). 800 Joules
d). 93.75%
You're welcome.
And #27 is 0.667 m/s .
Answer:
When energy contained in coal is turned into heat, and then into electrical energy. As boiling water heated by the burning coal is cooled, steam forges from these cone-shaped cooling towers.
Answer:
The crust is the first layer of the earth. It is split up into two parts the continental crust, and the oceanic crust. The oceanic crust takes up 71% of the earths crust, and the other 29% of the crust is continental. The continental is made up of igneous rocks, and the oceanic crust is made up of sedimentary and basalt rocks. The continental crust is older than the oceanic crust, some of the rocks are 3.9 billion years old. The density average of the oceanic crust is 3g/cm. The average density of the continental earth is 2.7g/cm. The temperature of the crust is around 200-400 degrees Celsius. The crust is about 60 km thick under a continent and 5 km thick under the ocean. The crust is constantly moving. The crust doesn't even make up 1% of the earth! The crust is the layer were tectonic plates can be found.
Explanation:
Answer:25.61 m/s
Explanation:
Given
truck is moving eastbound with a velocity of 16 m/s
Velocity of truck ![v_t=16\hat{i}](https://tex.z-dn.net/?f=v_t%3D16%5Chat%7Bi%7D)
SUV is moving south with a velocity of 20 m/s
Velocity of SUV in vector form ![v_s=-20\hat{j}](https://tex.z-dn.net/?f=v_s%3D-20%5Chat%7Bj%7D)
Velocity of truck relative to the SUV
![v_{ts}=v_{t}-v_s](https://tex.z-dn.net/?f=v_%7Bts%7D%3Dv_%7Bt%7D-v_s)
![v_{ts}=16\hat{i}-(-20\hat{j})](https://tex.z-dn.net/?f=v_%7Bts%7D%3D16%5Chat%7Bi%7D-%28-20%5Chat%7Bj%7D%29)
Magnitude of relative velocity is
![|v_{ts}|=\sqrt{16^2+20^2}](https://tex.z-dn.net/?f=%7Cv_%7Bts%7D%7C%3D%5Csqrt%7B16%5E2%2B20%5E2%7D)
Answer:
Frequency, f = 0.63 Hz
Period, T = 1.58 s
Speed of a wave, v = 1.34 m/s
Explanation:
The equation of a wave is given by :
...(1)
y is in mm
x is in meters
t is in seconds
The general equation of a wave is given by :
...(2)
(i) Compare equation (1) and (2) we get :
![k=3\\\\\omega=4](https://tex.z-dn.net/?f=k%3D3%5C%5C%5C%5C%5Comega%3D4)
Since,
![\omega=2\pi f\\\\f=\dfrac{\omega}{2\pi}\\\\f=\dfrac{4}{2\pi}\\\\f=0.63\ Hz](https://tex.z-dn.net/?f=%5Comega%3D2%5Cpi%20f%5C%5C%5C%5Cf%3D%5Cdfrac%7B%5Comega%7D%7B2%5Cpi%7D%5C%5C%5C%5Cf%3D%5Cdfrac%7B4%7D%7B2%5Cpi%7D%5C%5C%5C%5Cf%3D0.63%5C%20Hz)
(ii) Period of wave is :
![T=\dfrac{1}{f}\\\\T=\dfrac{1}{0.63}\\\\T=1.58\ s](https://tex.z-dn.net/?f=T%3D%5Cdfrac%7B1%7D%7Bf%7D%5C%5C%5C%5CT%3D%5Cdfrac%7B1%7D%7B0.63%7D%5C%5C%5C%5CT%3D1.58%5C%20s)
(iii) Speed of a wave,
![v=\dfrac{\omega}{k}\\\\v=\dfrac{4}{3}\\\\v=1.34\ m/s](https://tex.z-dn.net/?f=v%3D%5Cdfrac%7B%5Comega%7D%7Bk%7D%5C%5C%5C%5Cv%3D%5Cdfrac%7B4%7D%7B3%7D%5C%5C%5C%5Cv%3D1.34%5C%20m%2Fs)