Answer:v=41.23 m/s
Explanation:
Given
mass of heavy object 
distance of
from the axle 
mass of rock 
Length of rod 
distance of
from axle 
Net torque acting is




Work done by
is converted to rock kinetic Energy
thus

Where 





The speed of a electron that is accelerated from rest through an electric potential difference of 120 V is 
<h3>
How to calculate the speed of the electron?</h3>
We know, that the energy of the system is always conserved.
Using the Law of Conservation of energy,
U=0
Here, K is the kinetic energy and U is the potential energy.
Now, substituting the formula of U and K, we get:
=0------(1)
Here,
m is the mass of the electron
v is the speed of the electron
q is the charge on the electron
V is the potential difference
Let
and
represent the final and initial speed.
Here,
=0
Solving for
, we get:


=6.49
m/s
To learn more about the conservation of energy, refer to:
brainly.com/question/2137260
#SPJ4
Answer:
Zeros that follow non-zero numbers and are also to the right of a decimal point are significant.
Explanation:
For example:
0.300 has 3 significant figures.
5.400 has 4 significant figures.