Answer:
option (A)
Explanation:
The a body having rest mass is mo is moving with velocity v which is of the order of velocity of light in vacuum, so the mass of the body increases. According to the formula

As the velocity increases, the mass m of the body increases. As the velocity of the object is equal to the velocity of light in vacuum, then the mass of the body becomes infinite.
Answer:
The couch will remain stationary
Explanation:
Friction is the force that resist/opposes the motion. It is the force that has to e overcome before an object can move.
Since the frictional force of 50 N is required before the couch can move, applying 25 N can not overcome the frictional force of 50 N, so the couch will remain stationary.A force greater than 50 will be require to set the couch in motion
Answer:
Mass of the planet = 1.48 × 10²⁵ Kg
Mass of the star = 5.09 × 10³⁰ kg
Explanation:
Given;
Diameter = 1.8 × 10⁷ m
Therefore,
Radius =
=
or
Radius of the planet = 0.9 × 10⁷ m
Rotation period = 22.3 hours
Radius of star = 2.2 × 10¹¹ m
Orbit period = 407 earth days = 407 × 24 × 60 × 60 seconds = 35164800 s
free-fall acceleration = 12.2 m/s²
Now,
we have the relation
g =
g is the free fall acceleration
G is the gravitational force constant
M is the mass of the planet
on substituting the respective values, we get
12.2 =
or
M = 1.48 × 10²⁵ Kg
From the Kepler's law we have
T² =
on substituting the respective values, we get
35164800² =
or
= 5.09 × 10³⁰ kg
Answer:
(a) The force between them quadruples
Explanation:
According to coulomb's law, initial force between the two charged objects is given as;

where;
k is coulomb's constant
q₁ is the charge on the first object
q₂ is the charge on the second object
r is the distance between the two objects
When the charges on both objects are doubled, then;
q₁ = 2q₁
q₂ = 2q₂
Force between the two charged objects will become

Therefore, the force between them quadruples
Explanation:
V=IR; I=V/R
V=120V, R=10
I= 120/10=12
The current in the circuit is 12A