How do you calculate the "change in speed"?

Related questions

• What is the difference between distance and displacement?
• Is displacement directly proportional to velocity?
• How does average velocity differ from instantaneous velocity?
• How can I calculate the change of velocity?
• How do speed and velocity differ from each other?
• How do velocity and acceleration differ?
• How do displacement and distance differ?
• Can displacement be negative?
• Can velocity be zero if accelerating?
• Explain why displacement is a vector quantity?