Answer:

Explanation:
An object is at rest along a slope if the net force acting on it is zero. The equation of the forces along the direction parallel to the slope is:
(1)
where
is the component of the weight parallel to the slope, with m being the mass of the object, g the acceleration of gravity,
the angle of the slope
is the frictional force, with
being the coefficient of friction and R the normal reaction of the incline
The equation of the forces along the direction perpendicular to the slope is

where
R is the normal reaction
is the component of the weight perpendicular to the slope
Solving for R,

And substituting into (1)

Re-arranging the equation,

This the condition at which the equilibrium holds: when the tangent of the angle becomes larger than the value of
, the force of friction is no longer able to balance the component of the weight parallel to the slope, and so the object starts sliding down.
Momentum = Mass x Velocity
Put the values where they belong and solve for Velocity.
In this case, since Mass is being multiplied by Velocity, to solve for be Velocity you would divide both sides by Velocity. The velocity will equal the momentum divided by the mass.
Answer:
Explanation:
Given

Em wave is in the form of

where 


Wave constant for EM wave k is

Wavelength of wave 


Answer:
88.3
Explanation:
Emf in a rotating coil is given by rate of change of flux:
E= dФ/dt=(NABcos∅)/ dt
N: number of turns in the coil= 80
A: area of the coil= 0.25×0.40= 0.1
B: magnetic field strength= 1.1
Ф: angle of rotation= 90- 37= 53
dt= 0.06s
E= (80 × 0.4× 0.25×1.10 × cos53)/0.06= 88.3V
(a) Both the girl and the boy have the same nonzero angular displacement.
Explanation:
The angular displacement of an object moving in uniform circular motion, as the boy and the girl on the merry-go-round, is given by

where
is the angular speed
t is the time interval
For a uniform object in uniform circular motion, all the points of the object have same angular speed. This means that the value of
is the same for the boy and the girl.
Therefore, if we consider the same time interval t, the boy and the girl will also have same nonzero angular displacement.
(b) The girl has greater linear speed.
Explanation:
The linear (tangential) speed of a point along the merry-go-round is given by

where
is the angular speed
r is the distance of the point from the centre of the merry-go-round
In this problem, the girl is near the outer edge, while the boy is closer to the centre: since the value of
is the same for both, this means that the value of r is larger for the girl, so the girl will also have a greater linear speed.