AQA A Level Maths: Mechanics复习笔记2.5.1 suvat in 2D

What are the 2D/vector suvat formulae?

• Given that acceleration is constant, four of the five suvat formulae can be used with vector

How do I use the 2D/vector suvat formulae?

• The skills involved are the same for suvat in 1D
• Acceleration must be constant
  • If acceleration varies with time then you need to use calculus

   

• All the suvat equations connect four of the five quantities
  • Knowing any three allows a fourth to be found

   

• Any vector quantity used within the suvat equations (s, u, v and a) are split into i and j- components, time is a scalar and is used as normal
  • You can use one vector equation and solve that or split into two equations (one for each component) and solve them separately

   

Are there any additional problems with suvat when working in 2D?

• Sometimes they won’t give you the velocity instead it could say “…a particle is travelling parallel to…”
  • This means its velocity is a scalar multiple of that vector
  • If the object is travelling parallel to the vector i then the component of velocity in the j direction must be zero and vice versa

   

• The question could ask for speeds and/or distances
  • You will need to find magnitudes of relevant vectors

   

(a)  Find the acceleration of the drone, giving your answer in the form  .

(b)  Find the distance of the drone from its starting point after one minute.