The answer is true. Gravity is the force that keeps us all on the ground.
Answer:8.75 s,
136.89 m
Explanation:
Given
Initial velocity
velocity after 5 s is 
Therefore acceleration during these 5 s


therefore time required to stop
v=u+at
here v=final velocity =0 m/s
initial velocity =31.29 m/s


(b)total distance traveled before stoppage


s=136.89 m
The electron is accelerated through a potential difference of

, so the kinetic energy gained by the electron is equal to its variation of electrical potential energy:

where
m is the electron mass
v is the final speed of the electron
e is the electron charge

is the potential difference
Re-arranging this equation, we can find the speed of the electron before entering the magnetic field:

Now the electron enters the magnetic field. The Lorentz force provides the centripetal force that keeps the electron in circular orbit:

where B is the intensity of the magnetic field and r is the orbital radius. Since the radius is r=25 cm=0.25 m, we can re-arrange this equation to find B:
What is he minumum coating of thickness needed to ensure that lifght of waveelntght 5660 mbnd si
1. b or c
2. c
3. a? or d
4.
5. a