Is a physical change because only the state of the matter has changed.
Physical changes can often be reversed. Allowing the water to evaporate will return the salt to a solid state.
It has not combined with the water to cause an irreversible chemical reaction.
I don't think that 4m has anything to do with the problem.
anyway. here.
A___________________B_______C
where A is the point that the train was released.
B is where the wheel started to stick
C is where it stopped
From A to B, v=2.5m/s, it takes 2s to go A to B so t=2
AB= v*t = 2.5 * 2 = 5m
The train comes to a stop 7.7 m from the point at which it was released so AC=7.7m
then BC= AC-AB = 7.7-5 = 2.7m
now consider BC
v^2=u^2+2as
where u is initial speed, in this case is 2.5m/s
v is final speed, train stop at C so final speed=0, so v=0
a is acceleration
s is displacement, which is BC=2.7m
substitute all the number into equation, we have
0^2 = 2.5^2 + 2*a*2.7
0 = 6.25 + 5.4a
a = -6.25/5.4 = -1.157
so acceleration is -1.157m/(s^2)
I believe the answer is A
Answer:
0.56 atm
Explanation:
First of all, we need to find the number of moles of the gas.
We know that
m = 1.00 g is the mass of the gas
is the molar mass of the carbon dioxide
So, the number of moles of the gas is
Now we can find the pressure of the gas by using the ideal gas equation:
where
p is the pressure
is the volume
n = 0.023 mol is the number of moles
is the gas constant
is the temperature of the gas
Solving the equation for p, we find
And since we have
the pressure in atmospheres is
