1 / 9

speed

speed. Speed:. The speed of something is how fast it is moving. Speed is measured in: Metres per second: ms -1 Kilometres per hour: km/h or kmh -1 The formula for speed is: v=d/t v: means speed, the other name for speed is velocity d: is distance in metres t: is time in seconds.

ayasha
Download Presentation

speed

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. speed

  2. Speed: • The speed of something is how fast it is moving. • Speed is measured in: • Metres per second: ms-1 • Kilometres per hour: km/h or kmh-1 • The formula for speed is: v=d/t • v: means speed, the other name for speed is velocity • d: is distance in metres • t: is time in seconds

  3. E.g. Maureen and Megan studied whether cars passing their school were breaking the speed limit. • The speed limit outside the school was 50 km/h (14 ms-1 ). They measured 70m. Maureen waved as cars crossed a starting line on the road and Megan used a stopwatch to time how long it took them to cross the line in front of her. Any car that travelled the 70 m in less than 5 s was speeding. • v=d/t using this formula, complete the table on the next screen

  4. Acceleration and deceleration

  5. acceleration • Unbalanced forces produce a changing motion. If it speeds up the object, it is accelerating. • Acceleration is measured in metres per second per second: ms-2 . In other words, how much faster it goes in metres per second every second. • a=v/t. F=ma. • There are 2 formulas that have acceleration in them. • Acceleration = speed/time • Force = mass X acceleration

  6. Deceleration: • Deceleration is the slowing down of an object. We show deceleration by putting a negative sign in front of the number: • E.g. a car decelerates at -10 ms-2 .

  7. Changing equations:

  8. Changing equations • If we put the equation into a triangle, we can easily work out the other equations. • We put our finger over the thing we are trying to work out and then write down the equation. • v=d/t; • d=vt; • t=d/v d v t

More Related