Author Archives: mrmackenzie

H tension HW answers⤴

from @ fizzics

I’ve marked your HW jotters and will hand them back during tomorrow’s lesson. I’ll go over the main issues in class but many of you need to review the way you attempt tension questions; use a free body diagram and only use F=ma when you know the resultant force.  These two videos should help. HW ... Read more

Newton’s third law of motion⤴

from @ fizzics

Today we examined the importance of Newton’s 3rd law of motion. In our discussions, different explanations for the motion of jets and rockets were proposed and considered. The front runners were; at launch, the ground pushes back against a rocket during flight, air pushes back against a plane Unfortunately, the lack of ground and air (or ... Read more

using Excel’s LINEST function⤴

from @ fizzics

The period (T) of a simple pendulum can be calculated using where l is the pendulum length and g is the gravitational field strength. Using a single value of length and period, we can determine the acceleration due to gravity.  However, it would be better experimental practise to vary the length of the pendulum and ... Read more