1Which of these has the same dimensions as thrust?
Thrust and centripetal force both have the dimensions [M L T⁻²].
MechanicsClass 11, Laws of Motion
Dimensional formula of Thrust
[M L T-2]
The force that pushes a rocket or an aircraft forward. It is measured in newtons and has the dimension of force.
How to get the dimensional formula of thrust
- Start from the definition: thrust = force.
- velocity = length / time, so velocity is [L] / [T] = [L T-1].
- acceleration = velocity / time, so acceleration is [L T-1] / [T] = [L T-2].
- force = mass × acceleration, so force is [M] × [L T-2] = [M L T-2].
- Put in the dimension of each part: [M L T-2].
- Add the powers of each base quantity: [M L T-2].
Quantities with the dimensions [M L T⁻²]
Equal dimensions do not make them the same quantity. Compare thrust with the others in the full grid.
Three questions on thrust
2What is the SI unit of thrust?
The SI unit of thrust is the newton (N).
3Which one has different dimensions from the others?
Impulse is [M L T⁻¹]. The other three are all [M L T⁻²].
Thrust: quick answers
What is the dimensional formula of thrust?
The dimensional formula of thrust is [M L T⁻²]. It comes from thrust = force.
What is the SI unit of thrust?
The SI unit of thrust is the newton (N).
Which quantities have the same dimensions as thrust?
Thrust shares [M L T⁻²] with force, tension, centripetal force, weight. Equal dimensions do not make them the same quantity.