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Distance, speed and acceleration. Physics 2. Chapter 15. GCSE Additional Science. Distance, speed and acceleration. Speed = distance (metres) time (seconds). S. V × t. Click here for the answers. Aled walks 200m in 40s. What is his speed?
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Distance, speed and acceleration Physics 2 Chapter 15 GCSE Additional Science
Distance, speed and acceleration Speed = distance (metres) time (seconds) S V × t Click here for the answers • Aled walks 200m in 40s. What is his speed? • Lowri travels 2km in 1000s. What is her speed? • How long would it take for Dafydd to run 100m if he runs at a speed of 10m/s? • Heledd travels at a speed of 50m/s for 20s. How far does she travel? • A car travels at a speed of 85 mph (about 40m/s). How long would it take for him to travel 20km? 1) 5m/s 2) 2m/s 3) 10s 4) 1000m/s 5) 500s Chapter 15 GCSE Additional Science
Distance-Time Graphs 4) Straight line at a downwards angle = • 2) Straight horizontal line = 3) Straight line at a greater angle upwards = • Straight line at an upwards angle = 40 30 20 10 0 Motionless Constant speed in reverse Distance (metres) Chapter 15 GCSE Additional Science Time/s 20 40 60 80 100 Constant speed forwards (high) Constant speed forwards (low)
40 30 20 10 0 Distance (m) Time (s) 20 40 60 80 100 Chapter 15 Click here for the answers GCSE Additional Science • What is the speed during the first 20s? • How far is the object from the start after 60 seconds? • What is the speed during the last 40s? • When was the object travelling at its fastest? 1) 0.5m/s 2) 40m 3) 2m/s in reverse 4) 40 – 60s
Speed v Velocity This car’s speed is 20m/s Speed of 20m/s to the right Simply, speed is the distance travelled per second … Velocity is the distance travelled per second in a specific direction ….. Chapter 15 GCSE Additional Science
Acceleration change in velocity (m/s) acceleration (m/s2) = time (s) V - U a×t • A biker speeds up from 0 to 10m/s in 5 s. What is the acceleration? • A ball is dropped with an acceleration of 10m/s2 for 12s. By how much will the velocity of the ball change? • A car speeds up from 10 to 20m/s with an acceleration of 2m/s2. How much time did this change take? • A rocket speeds up from 1 000m/s to 5 000m/s in 2s. What is its velocity? Click here for the answers Chapter 15 1) 2m/s2 2) 120m/s 3) 5s 4) 2000m/s2 GCSE Additional Science
Velocity-Time Graphs • Line at an upwards angle = • 4) Line at a downwards angle = • 3) Line at an upwards angle = • 2) Horizontal line = 80 60 40 20 0 Constant acceleration Constant deceleration velocity (m/s) Chapter 15 GCSE Additional Science t(s) 10 20 30 40 50 Constant velocity Constant acceleration (lower)
Calculating the Distance 80 60 40 20 0 Velocity (m/s) t/s Chapter 15 GCSE Additional Science 10 20 30 40 50 To calculate the total distance of the journey, you must calculate the area under the graph.
80 60 40 20 0 Velocity (m/s) t/s 10 20 30 40 50 Chapter 15 Click here for the answers • What is the velocity after 10s? • What is the acceleration between 20 a 30s? • What is the deceleration between 30 and 50s? • What was the distance of the journey? GCSE Additional Science 1) 40m/s 2) 2m/s2 3) 3m/s2 4) 1700m