To solve this problem we will start from the given concept in which the number of turns is equivalent to the length of the thread per circumference of spool. That is:
Where,
l = length of the thread
= circumference of spool
For \phi we have that,
For l we have that
l = 62.8m
Finally the number of Turns would be,
Therefore the number of turns of thread on the spool are 1000turns.
D because the tornado siren are supposed to be loud so everyone could hear
Answer:
1788.402 MJ
Explanation:
Work done = Force (N) x distance (m)
First we have to convert distance into metres:
173.8 x 1000 = 173,800 m
Then plug these values into the equation above:
173,800 x 10290 = 1788402000 J
The reason it's Joules (the unit for energy) is because work done = energy transferred
Now we have to convert Joules into Mega Joules:
1 J = 1/1000000 MJ
1788402000 J = 1788402000/ 1000000 = 1788.402 MJ
If the force applied(Fa) is pushing down to chair friction goes up. if Fa pushing up, friction goes down. if Fa pushing sideways and the chair stays stationary, friction stay the same. if Fa push sideway and chair moves, friction goes down