Answer:
He should stand from the center of laser pointed on the wall at 1.3 m.
Explanation:
Given that,
Wave length = 650 nm
Distance =10 m
Double slit separation d = 5 μm
We need to find the position of fringe
Using formula of distance



Put the value into the formula


Hence, He should stand from the center of laser pointed on the wall at 1.3 m.
The De Broglie wavelength of the electron is

And we can use De Broglie's relationship to find its momentum:

Given

, with m being the electron mass and v its velocity, we can find the electron's velocity:

This velocity is quite small compared to the speed of light, so the electron is non-relativistic and we can find its kinetic energy by using the non-relativistic formula:
Answer:
Option 5. 1 and 3
Solution:
The only forces acting on the tennis ball after it has left contact with the racquet and the instant before it touches the ground are the force of gravity in the downward direction and the force by the air exerted on the ball.
The ball after it left follows the path of trajectory and as it moves forward in the horizontal direction the force of the air acts on it.
In the whole projectile motion of the ball, the acceleration due to gravity acts on the ball thus the force of gravity acts on the ball in the downward direction before it hits the ground.
Answer:
7976 Pascals significant figure= 7.9*10^3
Explanation:
formula of hpg = height*density*gravitational energy
.80*10*997=7976 pascals