Answer: Part(a)=0.041 secs, Part(b)=0.041 secs
Explanation: Firstly we assume that only the gravitational acceleration is acting on the basket ball player i.e. there is no air friction
now we know that
a=-9.81 m/s^2 ( negative because it is pulling the player downwards)
we also know that
s=76 cm= 0.76 m ( maximum s)
using kinetic equation
![v^2=u^2+2as](https://tex.z-dn.net/?f=v%5E2%3Du%5E2%2B2as)
where v is final velocity which is zero at max height and u is it initial
hence
![u^2=-2(-9.81)*0.76](https://tex.z-dn.net/?f=u%5E2%3D-2%28-9.81%29%2A0.76)
![u=3.8615 m/s\\](https://tex.z-dn.net/?f=u%3D3.8615%20m%2Fs%5C%5C)
now we can find time in the 15 cm ascent
![s=ut+0.5at^2](https://tex.z-dn.net/?f=s%3Dut%2B0.5at%5E2)
![0.15=3.861*t+0.5*9.81t^2\\](https://tex.z-dn.net/?f=0.15%3D3.861%2At%2B0.5%2A9.81t%5E2%5C%5C)
using quadratic formula
![t=\frac{-3.861+\sqrt{3.86^2-4*0.5*9.81(-0.15)} }{2*0.5*9.81}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B-3.861%2B%5Csqrt%7B3.86%5E2-4%2A0.5%2A9.81%28-0.15%29%7D%20%7D%7B2%2A0.5%2A9.81%7D)
t=0.0409 sec
the answer for the part b will be the same
To find the answer for the part b we can find the velocity at 15 cm height similarly using
![v^2=u^2+2as](https://tex.z-dn.net/?f=v%5E2%3Du%5E2%2B2as)
where s=0.76-0.15
as the player has traveled the above distance to reach 15cm to the bottom
![v^2=0^2 +2*(9.81)*(0.76-0.15)](https://tex.z-dn.net/?f=v%5E2%3D0%5E2%20%2B2%2A%289.81%29%2A%280.76-0.15%29)
![v=3.4595](https://tex.z-dn.net/?f=v%3D3.4595)
when the player reaches the bottom it has the same velocity with which it started which is 3.861
hence the time required to reach the bottom 15cm is
![t=\frac{3.861-3.4595}{9.81}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B3.861-3.4595%7D%7B9.81%7D)
t=0.0409
Answer:
Due to Conservation of Energy just as the ball hits the ground it's potential energy is assumed zero
Therefore disregarding air resistance all energy is converted into potential energy.
So KE = PE
(5 J)
Answer:
C
Explanation:
Ray of light when hits any specimen or object. The light is partially reflected, partially reflected and partially absorbed. It is never completed reflected, refracted or absorbed. Hence, the correct answer would be c.
The correct answer to the question is : 1) Converting energy and 2) Within about twenty years, natural gas forms.
EXPLANATION:
In coal fired power plants, the water is heated by burning coals. The heat produced in this process will convert water into steam. The steam is allowed to rotate the turbine. The turbine is attached to a generator which converts the kinetic energy of the steam into electric energy due to electromagnetic induction.
Hence, turbine helps in converting energy.
As per the second question, Walt listed the steps that occur during the formation of natural gas.
The natural gas is produced due to natural phenomenon. For this, millions of years are passed. So, it is a long range process in which the fossil of animals and planets buried beneath the surface are converted into natural gas under high pressure.
Hence, the mistake of Walt is that the natural gas is produced withing twenty years.
One Celsius degree is the same size as one Kelvin. Each of them is the size of 1.8 Fahrenheit degrees.