W=Fd. Force is not given so we solve for it. F=ma, m=5kg, a=2m/s^2, F=10N. Distance is not given so we solve for it, x=.5a(t^2)=.5(2)(7x7)=49m. F=10N, d=49m, W=490J.
Nope. It's called 'centripetal' acceleration. The force that created it MAY be gravitational, but it doesn't have to be. For things on the surface of the Earth moving in circles, it's never gravity.
Answer:
Explanation:
The pail is rotated at a constant rate in vertical circular path so it has the minimum speed at all points along its circular path . That means at top position the velocity is almost zero. In that case the centripetal force at top position will be provided by its weight or
mg = mv² / r ( r is radius of vertical circular path )
v = √ rg
At the bottom position its velocity will be increased due to loss of potential energy
so 1/2 m V² = 1/2 m v² + mg x 2r
V =√ 5 gr
If R be the reaction force at the bottom by bottom of pail
R - mg = mV² / r
R = mg +mV² / r
= mg + m x 5gr / r
R = 6mg
This is the magnitude of the force exerted by the water on the bottom of the pail .
Answer:
to create the particle the speed must be greater than 2.25 10⁸ m / s
Explanation:
In this exercise we must use the relation of the index of refraction with the speed of light in a vacuum and a material medium
n = c / v
where c is the speed of light in the vacuum, v the speed of light in the material medium and n the ratio of rafraccio
in this case they give us that the medium matter water them that has a refractive index of
n = 1,333
we clear
v = c / n
let's calculate
v = 3 10⁸ / 1,333
v = 2.25 10⁸ m / s
to create the particle the speed must be greater than 2.25 10⁸ m / s
We need the frequency of the photon, it is v = c/ λ
Where c is 3 x 10^8 ms^-1 and λ
is the wave length
We also need the expression of
connecting frequency to energy of photon
which is E = hv where h is Planck’s
constant
Combining the two equations
will give us:
E = h x c/λ
Inserting the values, we will
have:
E = 6.626 x 10^-34 x 3 x 10^8 /
0.126
E = 1.578 x 10^ -24 J
