The atomic mass is roughly equal to the sum of protons and neutrons of an atom.
9 protons + 10 neutrons = 19
Atomic mass of Flourine is 19.
Answer:
-360 kJ
Explanation:
Given:
m = 800 kg
v₀ = 30 m/s
v = 0 m/s
Δx = 75 m
Find: W
We can solve this using either forces or energy.
To use forces, first find the acceleration.
v² = v₀² + 2aΔx
(0 m/s)² = (30 m/s)² + 2a (75 m)
a = -6 m/s²
Then apply Newton's second law:
∑F = ma
F = (800 kg) (-6 m/s²)
F = -4800 N
Work is force times distance:
W = FΔx
W = (-4800 N) (75 m)
W = -360,000 J
W = -360 kJ
If you want to use energy instead:
work = change in energy
W = ΔKE
W = ½mv² − ½mv₀²
W = ½ (800 kg) (0 m/s)² − ½ (800 kg) (30 m/s)²
W = -360,000 J
W = -360 kJ
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)
Answer:
Kinetic energy of the electron 
Explanation:
It is given that,
Initial speed of an electron, u = 660000 m/s
Final speed of the electron, v = 0 (at rest)
The kinetic energy of an electron is possessed due to the motion of an electron. The mathematical formula for the kinetic energy is given by :
m is the mass of electron
Since, 
So, the initial kinetic energy of the electron is 1.23 eV. Hence, this is the required solution.
