- #1
Ogakor
- 17
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Hi everyone! I am really bad in physics so I need help in my assignments. My problem is what formula to use. Here's the problems.
An electron (mass = 9.11 x 10-31 kg) leaves one end of a tv picture tube with zero (0) initial speed and travels in a straight line to the accelerating grid, which is 1.80 cm away. It reaches the grid with a speed of 3.00 x 1006 m/s; If the accelerating force is constant, compute:
a.) acceleration
b.) time to reach the grid
c.) net force in Newtons (gravitational force on the electron may be neglected)
given:
m = 9.11 x 10-31
vo = 0 m/s
vF = 3.00 x 1006
d = 1.80 cm = 0.018m
In A:
I've thought of two formulas. Both give different results. These are:
a = v/t
Since there is no TIME, I will have to solve for time using:
t = m(v - vo) / F
The other formula I have thought of is:
a = v2 / 2x (from v2 = vo2 + 2ax)
In B:
It's either:
t = m(v - vo) / F
or
t = d/v
both giving different results again
In C:
It's obviously F = ma...
Please help me, I really don't know what formula to use.
Homework Statement
An electron (mass = 9.11 x 10-31 kg) leaves one end of a tv picture tube with zero (0) initial speed and travels in a straight line to the accelerating grid, which is 1.80 cm away. It reaches the grid with a speed of 3.00 x 1006 m/s; If the accelerating force is constant, compute:
a.) acceleration
b.) time to reach the grid
c.) net force in Newtons (gravitational force on the electron may be neglected)
given:
m = 9.11 x 10-31
vo = 0 m/s
vF = 3.00 x 1006
d = 1.80 cm = 0.018m
In A:
I've thought of two formulas. Both give different results. These are:
a = v/t
Since there is no TIME, I will have to solve for time using:
t = m(v - vo) / F
The other formula I have thought of is:
a = v2 / 2x (from v2 = vo2 + 2ax)
In B:
It's either:
t = m(v - vo) / F
or
t = d/v
both giving different results again
In C:
It's obviously F = ma...
Please help me, I really don't know what formula to use.