A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?
2 answers:
Answer:
The motorist average speed for the trip is 88 km/h
Explanation:
In order to know her average speed, we have to refer to the following ecuation:
<V> (average speed) =
So, according to that, we know that the motorist has been having a speed of 80km/h during 3 hours, and a speed of 100 km/h during 2 hours. It means that her speed during all the travel is 5 hours.
Then, we have to affect the 5 hours to the inicial and final speed as follows:
First, at 80 km/h, she travels during 2 hours so:
3h*80km/h= 240 km
And then, at 100 km/h:
2h*100km/h= 200 km
Which leads us to:
initial speed: 240 km/ 5 h= 48 km/h
and final speed of: 200 km/ 5 h= 40 km/h
Then, the average speed is:
<V> = 48 km/h + 40 km/h = 88 km/h
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I have attached the image showing the 6 combination of charges
Answer:
Smallest are: q1 = +1 nc, q2 = +1 nc, q3 = +1 nc and q1 = -1 nc, q2 = -1 nc, q3 = -1nc
Third Largest: q1 = +1 nc, q2 = +1nc, q3 = -1 nc
Second Largest: q1 = +1 nc, q2 = -1 nc, q3 = +1 nc
Largest are: q1 = +1 nc, q2 = -1 nc, q3 = -1 nc and q1 = -1 nc, q2 = +1 nc, q3 = +1 nc
Explanation:
The electrostatic force between 2 charges is; F = k•q1•q2/r²
Where r is the distance between the 2 charges q1 and q2 and k is coulombs constant.
Thus;
F ∝ q1•q2/r²
The net force on the charge q1 is the sum of the forces on charge q2 and q3.
If the two charges are opposite, the force is an attractive force while if the two charges are similar, the force is a repulsive force.
Thus, if the combination has same type of charges, i.e;(+1,+1,+1) or (-1,-1,-1), the force will be very small.
So, now the order of forces from smallest to largest is;
Smallest are: q1 = +1 nc, q2 = +1 nc, q3 = +1 nc and q1 = -1 nc, q2 = -1 nc, q3 = -1nc
Third Largest: q1 = +1 nc, q2 = +1nc, q3 = -1 nc
Second Largest: q1 = +1 nc, q2 = -1 nc, q3 = +1 nc
Largest are: q1 = +1 nc, q2 = -1 nc, q3 = -1 nc and q1 = -1 nc, q2 = +1 nc, q3 = +1 nc
