Answer:(a)9.685 mm
(b)4.184 mm
Explanation:
Given
Wavelength of light 
Width of slit(b)=0.210
(a)Width of central maximum located 1.80m from slit


=9.685 mm
(b)Width of the first order bright fringe



I'm Pretty sure it's FRICTION
The answer is a tell me if I am wrong.
Answer:
v = 4.1 m/s
Explanation:
As per mechanical energy conservation law we can say that initial total gravitational potential energy of the sphere is equal to final kinetic energy of rolling
so we will say

now for pure rolling condition we know that

so we will have


now we will have



Acceleration is given by:

where
v is the final velocity
u is the initial velocity
t is the time interval
Let's apply the formula to the different parts of the problem:
A) 
Let's convert the quantities into SI units first:


t = 4.0 min = 240 s
So the acceleration is

B) 
As before, let's convert the quantities into SI units first:


t = 94 s
So the acceleration is

C) 
For this part we have to use a different formula:

where we have
v = 0 is the final velocity
u = 89.2 m/s is the initial velocity
a is the acceleration
d = 75 m is the distance covered
Solving for a, we find
