Answer:
The speed of proton when it emerges through the hole in the positive plate is
.
Explanation:
Given that,
A parallel-plate capacitor is held at a potential difference of 250 V.
A A proton is fired toward a small hole in the negative plate with a speed of, 
We need to find the speed when it emerges through the hole in the positive plate. It can be calculated using the conservation of energy as :

So, the speed of proton when it emerges through the hole in the positive plate is
.
There are four quantum numbers:
1) Principal quantum number which tells the shell in which the electron is and is an integer number starting from 1. Both of these electrons are in the same shell, the third.
2) Azimuthal quantum number which tells the subshell of the electron. This has a value of an integer starting from 0, 0 being the s orbital. The first electron is in the d orbital due to the number being 2 and the second is in the p orbital due to the number being 1.
3) Magnetic quantum number tells the orbital within the subshell. The first electron is in the -1 orbital of the d subshell (which has values from -2 to 2) and the second is in the -1 orbital of the p subshell (which has values from -1 to 1).
4) Spin quantum number which specifies the spin on the electron, both of the electrons have the same spin.
Answer:
Explanation:
Change in length of spring = 2.13 m
Component of weight acting on spring = mg sinθ
so
mg sinθ = k x where k is spring constant and x is total stretch due to force on the spring.
Here x = 2.13
mg sin17 = k x 2.13
31 x 9.8 sin17 = k x 2.13
k = 41.7 N/m
b ) In case surface had friction , spring would have stretched by less distance .
It is so because , the work done by gravity in stretching down is stored as potential energy in spring . In case of dissipative force like friction , it also takes up some energy in the form of heat etc so spring stretches less.
Answer:
72
Explanation:
The displacement of an object can be found from the velocity of the object by integrating the expression for the velocity.
In this problem, the velocity of the sport car is given by the expression

In order to find the expression for the position of the car, we integrate this expression. We find:

where C is an arbitrary constant.
Here we want to find the displacement after 3 seconds. The position at t = 0 is

While the position after t = 3 s is

Therefore, the displacement of the car in 3 seconds is
