Work done against gravity to climb upwards is always stored in the form of gravitational potential energy
so we can say

here h = vertical height raised
so here we know that

here we have

now from above equation


so work done will be given by above value
Answer:
speed = 7.9 m/s
Explanation:
speed = total distance / time taken
speed = 300 / 38
speed = 7.89473684 m/s
to the nearest tenth
speed = 7.9 m/s
Answer:
Given that refractive index of the material is √2. i.e. n = √2. Hence, critical angle for the material is 45°
Answer:
The distance is
Explanation:
From the question we are told that
The initial speed of the electron is 
The mass of electron is 
Let
be the distance between the electron and the proton when the speed of the electron instantaneously equal to twice the initial value
Let
be the initial kinetic energy of the electron \
Let
be the kinetic energy of the electron at the distance
from the proton
Considering that energy is conserved,
The energy at the initial position of the electron = The energy at the final position of the electron
i.e

are the potential energy at the initial position of the electron and at distance d of the electron to the proton
Here 
So the equation becomes

Here
are the charge on the electron and the proton and their are the same since a charge on an electron is equal to charge on a proton
is electrostatic constant with value 
i.e
is the velocity at distance d from the proton = 2
So the equation becomes

![\frac{1}{2} mv_i^2 = 4 [\frac{1}{2}mv_i^2 ]- \frac{k(q)^2}{d}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20mv_i%5E2%20%20%3D%204%20%5B%5Cfrac%7B1%7D%7B2%7Dmv_i%5E2%20%5D-%20%5Cfrac%7Bk%28q%29%5E2%7D%7Bd%7D)
![3[\frac{1}{2}mv_i^2 ] = \frac{k(q)^2}{d}](https://tex.z-dn.net/?f=3%5B%5Cfrac%7B1%7D%7B2%7Dmv_i%5E2%20%5D%20%3D%20%5Cfrac%7Bk%28q%29%5E2%7D%7Bd%7D)
Making d the subject of the formula



Exert force upward.
Like when you pick something up from the floor, or walk up the stairs.