Momentum is one of those things that are 'conserved' (like energy). That means the total amount of momentum in an isolated system is the same after some event as it was before the event.
Before the ear-splitting explosion, while the firecracker and the billiard balls were just sitting there on the frictionless table, the momentum of the system was zero, because nothing was moving. Right there, that tells us that the total momentum of all the balls and the fragments of the firecracker ... if you add up all the momentum vectors AFTER the explosion ... the sum is still zero. (D)
Answer:
Explanation:
Remark
This is a momentum question. Both cars are sitting still (v1 and v2 are both 0) to start with). When the spring is sprung), they both move but in opposite directions.
Let us say that v4 is minus.
Equation
0 = m3*v3 - m4* v4
Givens
m3 = 1750 kg
m4 = 1000 kg
v3 = 4 m/s
Solution
m3*4m/s - m4*x = 0
1750 * 4 - 1000*x = 0
1750 * 4 = 1000x
7000 = 1000 x
7000/1000 = x
x = 7 m/s
The biggest thing you're doing wrong is ignoring the units
when you're working with the quantities.
Now let's look at the rest of the problem:
The formula you used is correct:
Net flux through the surface = (net charge inside) / ε₀
and ε₀ = 8.85 x 10⁻¹² farad/meter.
What's the net charge inside the surface in this problem ?
It's (5.85 x 10⁷ electrons) x (the charge on each electron)
= (5.85 x 10⁷ electrons) x (-1.6 x 10⁻¹⁹ coulomb/electron)
= -9.36 x 10⁻¹² coulomb .
Finally, (net charge inside) / ε₀
= (-9.36 x 10⁻¹² coulomb) / (8.85 x 10⁻¹² farad/meter)
= -1.058 newton-m²/coulomb .
The sign and the significant figures in your answer are correct, so
we can see that you know what you're doing. The only thing left is
the order of magnitude. You most likely took one of the negative
exponents and made it positive. You got an answer that's 10²² too
small. Big deal. You could claim "that's close", and see whether you
can convince a teacher.
let the moles of chlorine-35 is n1 and chlorine-37 is n2
now we will use the formula of average atomic mass
here let say
so here since ratio of moles of chlorine 35 and chlorine 37 is more than 1 so chlorine 35 is more in the proportion in this mixture so <em>there is most chlorine atom consist of 18 neutrons</em>
Answer:
the molecules get close together and the water expands
Explanation: