Answer:
How much does a hair weigh in MG?
An average hair (about six inches in length) weighs about 0.2-0.4 milligrams or 0.00015 ounces. A healthy person has anywhere between 80,000 and 120,000 hairs on their head.
Explanation:
Answer:
the statement is TRUE
Explanation:
When we move in the same direction, the relative speed of the two vehicles is lower, so we must subtract their speeds, if the result is positive the vehicles approach and if it is negative they move away.
v_relative = v₁ - v₂
When the two vehicles go in opposite directions, the speed is much higher, so we must add their speeds
v_relative = v₁ - (-v₂))
v_relative = v₁ + v₂
therefore the statement is TRUE
Answer:
W= 38.4 J
Explanation:
Given that
m = 80 g= 0.08 kg
Initial speed ,u= 22 m/s
Final speed ,v= 38 m/s
The change in the kinetic energy of the particle


ΔKE= 38.4 J
We know that
Work done by all the forces =Change in the kinetic energy
That is why net work done = 38.4 J.
W= 38.4 J
Therefore the answer will be 38.4 J.
Answer:
0.19
Explanation:
mass of block, m = 40 kg
F = 150 N
Angle make with the horizontal, θ = 60 degree
Let μ be the coefficient of kinetic friction
The component of force along horizontal direction is F Cos θ
= 150 cos 60 = 75 N
As it is moving with constant velocity it mean the acceleration of the block is zero.
Applied force in horizontal direction = friction force
75 = μ x Normal reaction
75 = μ x m x g
75 = μ x 40 x 9.8
μ = 0.19
Thus, the coefficient of kinetic friction is 0.19.