A baseball bat hits a ball is an example of contact force.
Option A.
<h3><u>Explanation:</u></h3>
Contact force is defined as those forces which are acting between two bodies by actually touch between two bodies.
In case of the book falling to ground, the force acting is the gravitational force. Gravitational force acts even when two bodies aren't in contact. So its a non contact force.
Similar is the condition of the leaf and ground where the gravitational force acts.
The magnetic force between the paper clip and the magnet is also non contact force, which acts even when two bodies aren't in contact.
But the bat hitting the ball is having direct contact between the two bodies, and their contact is what makes the ball fly off. So its a contact force.
Answer:
in first case the torque is maximum.
Explanation:
Torque is defined as the product of force and the perpendicular distance.
τ = F x d x Sinθ
In case A: the angle between force vector and the distance vector is 90 so torque is
τ = F x d
In case B: the angle between force vector and the distance is 30°.
τ = F x d x Sin30
τ = 0.5 Fd
So the torque is maximum in first case.
Answer:
The value of radiation pressure is 
Pa
Explanation:
Given:
Intensity 
Area of piece 
From the formula of radiation pressure in terms of intensity,
Where 
radiation pressure, 
speed of light
We know value of speed of light,
Put all values in above equation,
Pa
Therefore, the value of radiation pressure is Pa
Lipids are found in the sugars and starches, and are the main sources of energy in the body.
