Answer:
a

b

Explanation:
From the question we are told that
The mass of the rock is 
The length of the small object from the rock is 
The length of the small object from the branch 
An image representing this lever set-up is shown on the first uploaded image
Here the small object acts as a fulcrum
The force exerted by the weight of the rock is mathematically evaluated as

substituting values


So at equilibrium the sum of the moment about the fulcrum is mathematically represented as

Here
is very small so
and 
Hence

=> 
substituting values


The mechanical advantage is mathematically evaluated as

substituting values


The weight of the person is given by:
W = mg
W = weight, m = mass, g = gravitational acceleration
Given values:
m = 40kg, g = 9.81m/s²
Plug in and solve for W:
W = 40(9.81)
W = 390N
If you are involved in a collision, it's important that you stop your car and protect others, as well as your self, from oncoming traffic. If you do not stop, you will have an arrest warrant against your name as it can safely be considered a 'hit and run.'
Answer:
m
Explanation:
= slit width = 0.1 mm = 0.1 x 10⁻³ m
= wavelength of monochromatic light = 500 nm = 500 x 10⁻⁹ m
= Distance of the screen = 10 m
= Spacing between successive minima
Spacing between successive minima is given as

Inserting the values given

m

Actually Welcome to the Concept of the Kinematics.
1.) Distance travelled = 15+20 = 35 miles.
Ai the total distance covered is 35 miles.
2.) Displacement is the shortest distance from the initial point to the final point.
here it's ==> 20-15 = 5 miles
hence, displacement = 5 miles