Answer:
Explanation:
Given
mass of boy 
mass of girl 
speed of girl after push 
Suppose speed of boy after push is 
initially momentum of system is zero so final momentum is also zero because momentum is conserved




i.e. velocity of boy is 2.82 m/s towards west
Answer:
Mass has total mechanical energy, which is the sum of kinetic and potential energy. as the mass is dropping, potential energy is converted into kinetic energy so mechanical energy is preserved If there is no friction. If there is friction, some of the mechanical energy is lost as heat energy so it changes.
Explanation:
The coefficient of static friction between the chair and the floor is 0.67
Explanation:
Given:
Weight of the chair = 25kg
Force = 165 N (F_applied)
Force = 127 N (F_max)
To find: Coefficient of static friction
The “coefficient of static friction” between a chair and the floor is defined as the ration of maximum force to the normal force acting on the chair
μ_s=
The F_n is equal to the weight multiplied by its gravity
∴
=mg
Thus the coefficient of static friction changes as
μ_s=
μ_{s} = 
= 0.67
Answer:
Part a)
h = 0.86 cm
Part b)
Level will increase
Explanation:
Part a)
Mass of the ice cube is 0.200 kg
Now from the buoyancy force formula we know that weight of the ice is counter balanced by buoyancy force on the ice
So here we will have



now as we know that ice will melt into water
so here volume of water that will convert due to melting of ice is given as


So here extra volume that rise in the level will be given as



Part b)
Since volume of water that formed here is more than the volume that is displaced by the ice so we can say that level of liquid in the cylinder will increase due to melting of ice