There are three forces acting on the book.
1. Force due to gravity
2. Force exerted downward by the hamster
3. Normal Force in reaction to the downward forces
Since the book is not moving, the net force is zero. The summation of all forces must be zero. Then we could find the normal force which is unknown (denoted as x).
∑F = -(4 kg)(9.81 m/s2) - 3 N + x =0
∑F = -39.24 N - 3N + x =0
x = 42 N
Therefore, the normal force is 42 N.
<h2>
Answer:Radiation-3,Conduction-1,Convection-2</h2>
Explanation:
Radiation is the transfer of heat through electromagnetic waves.
These waves do not require any medium.This is the way we get heat from sun.Radiation is the quickest mode to transfer of heat.
Conduction is the transfer of heat through collisions of atomic particles.
This phenomenon largely occurs in solids like metals.The neighbour atoms sets the atoms into random motion thereby raising the temperature.
Convection is the transfer of heat through actual movement of medium particle.
This phenomenon occurs in gases an liquids.The medium particles actually traverse through the space transferring the heat.
Answer:
The size of the image is 1.04 m.
Explanation:
Given that,
Height of object = 2.40 m
Distance of object = 2.60 m
Radius of curvature =4.00 m
Focal length 
We need to calculate the image distance
Using mirror formula




We need to calculate the height of the image
Using formula of magnification

Put the value into the formula



Hence, The size of the image is 1.04 m
If only internal forces are doing work (no work done by external forces), then there is no change in the total amount of mechanical energy. The total mechanical energy is said to be conserved. ... In these situations, the sum of the kinetic and potential energy is everywhere the same.