Rigidbody forces and velocity in Unity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Rigidbody in Unity?

A Rigidbody is a component that allows a GameObject to be affected by physics, like gravity and forces, making it move realistically.

beginner

How do you apply a force to a Rigidbody to make it move?

You use the Rigidbody's AddForce method, which pushes the object in a direction with a certain strength.

intermediate

What is the difference between setting Rigidbody.velocity directly and using AddForce?

Setting velocity changes the object's speed immediately, while AddForce applies a push that affects velocity over time based on mass and drag.

beginner

What does Rigidbody.useGravity control?

It controls whether the Rigidbody is affected by gravity. If true, gravity pulls the object down; if false, it floats.

intermediate

Why should you avoid setting Rigidbody.velocity every frame for smooth physics?

Because it overrides physics calculations and can cause unnatural movement. Using AddForce lets physics behave naturally.

Which method applies a continuous push to a Rigidbody in Unity?

A Translate

B SetPosition

C AddForce

D SetActive

AddForce applies a push that affects the Rigidbody's velocity over time.

What happens if you set Rigidbody.useGravity to false?

A The object will not be affected by gravity.

B The object will fall faster.

C The object will rotate automatically.

D The object will freeze in place.

Setting useGravity to false disables gravity's effect on the Rigidbody.

Directly setting Rigidbody.velocity will:

A Disable physics on the object.

B Apply a gradual force.

C Change the object's color.

D Instantly change the object's speed.

Setting velocity directly changes speed immediately, bypassing forces.

Which Rigidbody property affects how much the object resists movement?

A mass

B drag

C useGravity

D isKinematic

Drag slows down the Rigidbody's movement by resisting velocity.

To make a Rigidbody jump, you should:

A Use AddForce with an upward direction.

B Set velocity to zero.

C Disable gravity.

D Change the object's scale.

Applying an upward AddForce simulates a jump by pushing the Rigidbody up.

Explain how AddForce and velocity differ when moving a Rigidbody in Unity.

Think about how the object reacts immediately versus over time.

Describe what happens when you disable gravity on a Rigidbody and how it affects movement.

Imagine turning off Earth's pull on the object.