A child is standing on a walkway that is moving at 2 metres per second and decides to turn around and walk back to the start at 2 metres per second. Explain why the child cannot reach the start of the walkway at this speed.
Assuming that the walkway is moving in a positive direction, the child is walking in the opposite direction to it and is therefore walking in the negative direction. Both the child and the walkway have velocity, but their velocities are opposite since the direction they are moving in are directly opposite to eachother, however since they are moving at the same speed, the velocities will cancel out: -2+2=0. This result shows that in fact the child will not actually move and seem to be walking on the spot.
MS
Related Physics A Level answers
All answers ▸What is the most effective use of the equation sheet?
If a ball of mass 5kg is dropped from rest, how far will it travel in the 3 seconds after it reaches 150m from it's original position? Write down the change in it's total energy after the 3 seconds. (ignoring air resistance)
An ideal gas within a closed system undergoes an isothermal expansion from an initial volume of 1m^3 to 2m^3. Given that the initial pressure of the gas is 10^5 Pa, find the final pressure of the gas following the expansion.
What is Newton's Third Law and what is an example of it?