Answer:
(i) Relative velocity of B w.r.t A= Sum of speeds of trains
=54+90
=144kmph
(ii)Relative velocity of B w.r.t Ground(G)=v
B/G
=−90kmph
v
G
=0
Relative velocity of ground(G) w.r.t B =v
G/B
=v
G
−v
B/G
v
G/B
=0−(−90)
v
G/B
=90kmph
When material stuff is free to move, it moves away from stronger force on it to weaker force on it. OK ? Now take it to the next step: When material stuff is free to flow ... like liquid or gas ... it flows from higher pressure to lower pressure. That's what makes wind, and that's why water comes out of a garden hose when you open the nozzle. It doesn't amaze you at all when you INCREASE the pressure at one end of the straw (blow into it), and air moves DOWN and out of it. So it shouldn't bother you that when you DECREASE the pressure at your end, anything that's free to flow UP the straw will do that.
Answer:
0.056 psi more pressure is exerted by filled coat rack than an empty coat rack.
Explanation:
First we find the pressure exerted by the rack without coat. So, for that purpose, we use formula:
P₁ = F/A
where,
P₁ = Pressure exerted by empty rack = ?
F = Force exerted by empty rack = Weight of Empty Rack = 40 lb
A = Base Area = 452.4 in²
Therefore,
P₁ = 40 lb/452.4 in²
P₁ = 0.088 psi
Now, we calculate the pressure exerted by the rack along with the coat.
P₂ = F/A
where,
P₂ = Pressure exerted by rack filled with coats= ?
F = Force exerted by filled rack = Weight of Filled Rack = 65 lb
A = Base Area = 452.4 in²
Therefore,
P₂ = 65 lb/452.4 in²
P₂ = 0.144 psi
Now, the difference between both pressures is:
ΔP = P₂ - P₁
ΔP = 0.144 psi - 0.088 psi
<u>ΔP = 0.056 psi</u>
Newton I think. I could be wrong
Answer:
Explanation:
The sun keeps all of the planets in orbit around it. Without the sun, all of the planets would fly off into space (out of orbit)