Answer:
40 N
Explanation:
F=ma where F is the applied force, m is the mass of object and a is the acceleration.
Since there is no friction, substituting 20 Kg for m and 2 m/s squared for a then we obtain
F=20*2=40 N
Answer:
<em>W=700 Joule</em>
Explanation:
<u>Physics Work
</u>
Is the dot product of the force vector by the displacement vector

When both the force and the displacements are pointed in the same direction, the formula reduces to its scalar version

The weightlifter is applying a net force of 350 N to lift the weights a distance of 2 m, thus the net work done is

Explanation:
Let
are the number of turns in primary and secondary coil of the transformer such that,

A resistor R connected to the secondary dissipates a power 
For a transformer, 

...............(1)
The power dissipated through the secondary coil is :


.............(2)
Let
are the new number of turns in primary and secondary coil of the transformer such that,

New voltage is :

...............(3)
So, new power dissipated is 





So, the new power dissipated by the same resistor is 6400 watts. Hence, this is the required solution.
Answer:
the answer is C
Explanation:
we know this because if you compare the graphs and look at the direction. it isn't always in the explanation or the few sentences they gave you at the top. also, look at the waves, you can see in Davids drawing that it is directly straight up, A and B do not represent that. A isn't even a valid answer. Notice also in A that the arrow is going in the completely different direction than in Davids drawing. B is also going a different direction even though it is only turned a little bit although if it was straight up like Davids drawing then it would most likely be a correct answer. C does have one arrow going a different direction but look at how it has two, showing in which if the waves were to turn then the arrow is still valid
Fperson =[( velocity of wind )+ or - (velocity of person)] / [(velocity of wind) + or - (velocity of sounds)] x frekuency of sounds