Answer: 1.39 s
Explanation:
We can solve this problem with the following equations:
(1)
(2)
Where:
is the length the steel wire streches (taking into account 1mm=0.001 m)
is the length of the steel wire before being streched
is the force due gravity (the weight) acting on the pendulum with mass 
is the transversal area of the wire
is the Young modulus for steel
is the period of the pendulum
is the acceleration due gravity
Knowing this, let's begin by finding :
(3)
Where 
is the diameter of the wire
(4)
(5)
Knowing this area we can isolate from (1):
(6)
And substitute in (2):
(7)
(8)
Finally:
Answer:
0.8 x 10^-9 kg
Explanation:
Given,
Distance ( R ) = 10 m
Force ( F ) = 3.2 x 10^-9 N
Mass ( m1 ) = 40 kg
To find : Mass ( m2 ) = ?
Formula : -
F = m1.m2 / R^2
m2 = FR^2 / m1
= 3.2 x 10^-9 x 10 / 40
= 3.2 x 10^-9 / 4
= ( 3.2 / 4 ) x 10^-9
m2 = 0.8 x 10^-9 kg
The weight of the meterstick is:
and this weight is applied at the center of mass of the meterstick, so at x=0.50 m, therefore at a distance
from the pivot.
The torque generated by the weight of the meterstick around the pivot is:
To keep the system in equilibrium, the mass of 0.50 kg must generate an equal torque with opposite direction of rotation, so it must be located at a distance d2 somewhere between x=0 and x=0.40 m. The magnitude of the torque should be the same, 0.20 Nm, and so we have:
from which we find the value of d2:
So, the mass should be put at x=-0.04 m from the pivot, therefore at the x=36 cm mark.
Gravity lets all objects fall to the ground at the same speed, 9.8 m/s/s. If the force of gravity were stronger, such as 10 m/s/s, the rate of acceleration would be faster.
Answer:
A spinning turbine can generate electricity only in the form of an alternating current.
