Which of the following is a scalar? centripetal force
weight
speed
acceleration

Speed

Explanation:

- A scalar quantity is defined as a quantity which has a magnitude only (no direction)

- A vector quantity is defined as a quantity which has both a magnitude and a direction

Let's analyze each option:

- Centripetal force: force is a vector, because it has a magnitude and also a direction

- Weight: weight is a force, and force are vector quantities, so weight is a vector as well

- Speed: speed is a scalar quantity, because it has only a magnitude, no direction

- Acceleration: acceleration is a vector quantity, because it has a magnitude, but also a direction (because it represents the rate of charge in velocity, and since velocity is a vector, acceleration must be a vector as well)

So, the correct choice is

Speed

the first step is making objective observations.

they have to be based on a certain event and can be confirmed by others if it is right or not.