Answer:
The forces acting on the pen which is still on the table can have two forces acting on them. The forces are gravitational force and the equal and opposite force to the gravitational forces.
The equal and opposite forces that is applied on the pen keeps the pen still on the table.
So, the statement that no force is applied on the pen which is kept still on the table is wrong as two forces are applied on the pen.
As both the forces are equal and opposite so it is cancelled and is still.
Answer
The force on the left across the lab table.
Explanation
The Newton's third law of motion states that; <em>action and reaction are equal but a ct in opposite direction. </em>
When the block of is pulled on the right with a force of X Newtons then there is a force -X Newtons applying and equal force on the left. For every action there must be a reaction with is equal and applying in the opposite direction.
So, if the block is pulled on the right by a force of 8 N there is another equal force applying on the left.
Answer: 
Explanation:
Given
mass of laptop m=2 kg
The velocity of car u=8 m/s
The coefficient of static friction is 
The coefficient of kinetic friction is 
As the car is moving, so the coefficient of kinetic friction comes into play
deceleration offered by friction 
Using the equation of motion 
insert the values
Answer:
Both are attractive as well as repulsive.
Explanation:
(Like poles repel, like charges<em> repel</em>; unlike poles attract, unlike charges <em>attract</em>).
Answer:
(D) a brief early period of hyper rapid expansion of space-time.
Explanation:
Cosmic inflation is a theory which states that in an interval of 10⁻³⁶ seconds to around 10⁻³³ seconds after the big bang there was a massive expansion.
According to the big bang theory the universe came to be from a singularity i.e., a point of infinite gravitational field. The universe is expanding this means that according to the conservation of energy the universe was expanding from the beginning.
