In order to calculate the angle, we can use the formula below for a constructive interference (the interference is constructive because the fringe is bright):
Where d is the distance between the slits, m is the order of the interference and lambda is the wavelength.
So, using d = 8.25 * 10^-5, m = 2 and lambda = 4.5 * 10^-7, we have:
Therefore the correct option is the second one.
Explanation:
Assuming the wall is frictionless, there are four forces acting on the ladder.
Weight pulling down at the center of the ladder (mg).
Reaction force pushing to the left at the wall (Rw).
Reaction force pushing up at the foot of the ladder (Rf).
Friction force pushing to the right at the foot of the ladder (Ff).
(a) Calculate the reaction force at the wall.
Take the sum of the moments about the foot of the ladder.
∑τ = Iα
Rw (3.0 sin 60°) − mg (1.5 cos 60°) = 0
Rw (3.0 sin 60°) = mg (1.5 cos 60°)
Rw = mg / (2 tan 60°)
Rw = (10 kg) (9.8 m/s²) / (2√3)
Rw = 28 N
(b) State the friction at the foot of the ladder.
Take the sum of the forces in the x direction.
∑F = ma
Ff − Rw = 0
Ff = Rw
Ff = 28 N
(c) State the reaction at the foot of the ladder.
Take the sum of the forces in the y direction.
∑F = ma
Rf − mg = 0
Rf = mg
Rf = 98 N
Answer:
The correct answer is option B. coal
Explanation:
Coal is made of remains of organic material including trees and other vegetation which got trapped beneath the earth’s surface or at the bottom of the swamps. After burial below the ground the organic material was acted upon by the high temperature and pressure in the absence of air to form peat. Peat after further processing for a longer period of time converted into coal
Given that force is applied at an angle of 30 degree below the horizontal
So let say force applied if F
now its two components are given as
Now the normal force on the block is given as
now the friction force on the cart is given as
now if cart moves with constant speed then net force on cart must be zero
so now we have
so the force must be 199.2 N