The answer is B
I used these equations then i putted it together.
Charge = number of ( electron or proton ) x charge of ( electron or proton )
Force = k x (q1 q2)/r²
When a cold air <span>mass replaces a warm air mass, this is called a cold front. Some characteristics of a called front before passing are winds coming from south or southwest area, warm temperature, falling pressure, and drizzles. When it passes, the winds are shifting, there is a sudden drop of temperature, minimum pressure followed by a sharp rise. After passing, the winds head to the west or northwest area, temperature is steadily dropping and the pressure is rising steadily.</span>
Since they are rowing against the current, their velocity realtive to the groud is 20-1.5 = 18.5km/h
So the distance travelled is 18.5km/h*0.5h = 9.25km
Going back with the current their ground realative velocity is 20+1.5 = 21.5km/h so the time it takes them to return 9.25 km is 9.25km/(21.5km/h) = 0.43h ~= 26 min
Vector quantities are always defined by magnitude and its direction.
Here, to define number of coins in a piggy bank, we don't need direction. Hence it is a scalar quantity.
Answer: d. availability of places to play
Explanation: I think that it’s d because availability of space to do your physical activity is important. Availabilty of places to play is an environmental factor due to where you decide to play.