Top answers

How to we work out the speed of an object at a certain point in its trajectory?

This depends on the path of the object and what information you have. You could be looking at conservation of kinetic and gravitational potential energy. Total energy must be the same at all times. We can ma...
CC
Answered by Camilla C. • Physics tutor
2578 Views

A boy (25kg) and a girl (20kg) are playing on a see-saw which is 4m long. If the boy sits 1m from the centre on the left side and the girl 2m from the centre on the other, which direction will the see-saw will rotate around its centre?

Student should calculate the moments about the pivot point (from diagram recognise this is the centre of the see-saw) for each child. Using the equation, moment = mass x acceleration x distance from pivot, w...
JL
Answered by John L. • Physics tutor
2701 Views

A stationary unstable neutral particle decays into 2 separate particles with equal mass and velocity, what might the resulting bubble chamber diagram look like?

The two decayed particles will form identical spirals but in the opposite direction to one another, as they will have to be oppositely charged to preserve the overall charge. The spiral patterns will be iden...
PL
Answered by Patrick L. • Physics tutor
3415 Views

A cylindrical rod of radius 7mm and Young’s Modulus 70 GPa has a weight F applied to it. The material experiences a strain of 0.2%. What force has been applied?

Young's Modulus is defined as the ratio of stress to strain. E = stress/strain. Stress is the force per unit area, F/A. By substitution, we can see that E = F/(A x strain). Rearranging gives F = E x A x stra...
CW
Answered by Callum W. • Physics tutor
2614 Views

How come nuclei become more unstable the bigger they are?

The nucleus is made up of protons and nuetrons, which means there is an electric repulsion. The nucleus is held together by somethign called the strong nuclear force. This overrides the electromagnetic repul...
TR
Answered by Thomas R. • Physics tutor
3168 Views