Answer:
Explanation:
Given that
The speed of the airplane ,v= 142 m/s
The speed of the air ,u = 30 m/s
Lets take angle make by airplane from east direction towards north direction is θ .
Now by using diagram ,we can say that
Now by putting the values in the above equation we get
Therefore the angle will be 12.19° .
Force = mass x acceleration
15 = mass x 4
Mass = 15/4
Mass = 3.75 Kg
I think everything looks good but 2 might not be right, it might be B
"6.5 km/hr" is not a velocity. It's just a speed, so
we don't know what direction he's walking.
If he happens to be walking north, then it takes him
(12 km) / (6.5 km/hr) = 1.846... hours (rounded) .
If he's walking in any other direction, it takes him longer than that.
If the angle between north and the direction he's walking is
90 degrees or more, then he can never cover any northward
distance, no matter how long he walks.
When you look at this, you might not be sure which way to divide ...
Should you divide 6 by 5 or 5 by 6 ?
Here's a case where you can use your units to decide.
The question wants to know the 'period'. That's a length of time,
so the answer needs to have units of time.
If you divide 'cycles' be 'time', you'll get 'cycles/second'.
That's Hz. It's frequency, not time.
If you divide 'time' by 'cycles', you'll get 'seconds/cycle'.
That's time, and it's exactly the definition of 'period'.
Period = (6 seconds) / (5 cycles)
= (6 / 5) seconds/cycle
= 1.2 seconds
