Answer:
(B) The number of protons - only the number of protons in the nucleus determines the element - mass and neutrons can vary for the same element
It's just speed, distance, time
Speed = D/T
Distance = SxT
Time = D/S
Therefore Speed (or velocity) = D/T = 55/1.4 = 39 MPH rounded up - FOR JOURNEY 1
Velocity = D/T = 55/2 = 22.5 MPH - FOR JOURNEY 2
To work out his average speed (velocity) you add these together and divide by 2
Average = (39+22.5)/2
Answer = 30.75MPH or 31MPH rounded up
Hope this helps :) + If I'm wrong I'm sorry lol
If the machine doesn't decrease the amount of work that you do, it might still improve the quality of the final result of your efforts
I love this one. All the effects of gravity are vertical. There is no horizontal force on the crate, and we are neglecting air resistance, so the horizontal speed of the crate doesn't change. When it gets to the ground, its horizontal speed is still 100 meters per second.