Top answers

A lorry is travelling around a roundabout at constant speed. Why is its velocity changing?

Because velocity is a vector and therefore has both magnitude and direction. Thus as the lorry is changing direction whilst travelling around the roundabout its velocity is also changing (velocity = displace...
AL
Answered by Adam L. • Physics tutor
5226 Views

Is F=ma Newton's 2nd Laws of Motion?

That is a good question. F=ma is a special case of Newton's 2nd Law of Motion . Newton's second law states that: The rate of change of linear momentum is proportional to the applied force and acts in the sam...
MZ
Answered by Mohsin Z. • Physics tutor
15918 Views

What does "superimposition" mean?

Superimposition is when two transverse waves come together, and their frequencies cancel each other out. If the waves are completely superimposed, the resultant wave is 0.
SM
Answered by Sameer M. • Physics tutor
13400 Views

Why is potential energy negative? What does that even mean?

This is really just a definition! When we ask what the potential energy of an object is, we are really asking what energy is available to be extracted. In the case of gravity: two objects separated by an inf...
BT
Answered by Ben T. • Physics tutor
23229 Views

For a vehicule with a constant acceleration (5 m/s^2) starting at rest, how long would it take to travel 1 km?

as the acceleration is constant, to travel 1km=1000m, we use 1000 m =(1/2) (5 m/s^2) t^2, so t=sqrt(2 1000/5)=20 seconds
DR
Answered by David R. • Physics tutor
2649 Views