Answer:
1)the unit of work is joule. 2)it is derived unit because it is made by two different unit force and displacement .3)
Answer:
Explanation:
K.E is 1/2 mv^2
Therefore KE is 300000×10000×1/2
=1500000000J
= 1500000KJ
Potential energy is mgh
Therefore PE is 300000×9.8×2000
=5,880,000,000J
=5880000KJ
Answer:
Explanation:
Impulse of a force is measured by force x time or F X t
Impulse also equals change in momentum or
F x t = m v₂ - m v₁
The given case is as follows
in the first case
F x t = mv - o = mv
F = mv / t
in the second case
F₁ x 4 t = mv
F₁ = 1/4 x mv /t
F₁ = F / 4
option a) is correct .
iii )
In the last case
F₂ X t = m v/2 -0
F₂ = 1/2 x mv / t
= 1/2 x F
F₂ = F/2
Option e ) is correct.
Answer:
Explanation:
g = Acceleration due to gravity = 
= Angle of slope = 
v = Velocity of child at the bottom of the slide
= Coefficient of kinetic friction
= Coefficient of static friction
h = Height of slope = 1.8 m
The energy balance of the system is given by
The speed of the child at the bottom of the slide is
Length of the slide is given by
The force energy balance of the system is given by
The coefficient of kinetic friction is .
For static friction
So, the minimum possible value for the coefficient of static friction is .
Answer:
An atom always has the same number of electrons as protons. Electrons have an electric charge of -1 and protons have an electric charge of +1. Therefore, the charges of an atom's electrons and protons “cancel out.” This explains why atoms are neutral in electric charge.
Explanation:
