A car accelerates at a rate of 0·3 m/s2 for 15 seconds and reaches a speed of 18 m/s. What was its original speed? A bus travelling at a constant speed decelerates at 0·8 m/s2 for 4 s. If its speed drops to 12 m/s, what was the original speed of the bus?
Speed Distance Time Questions P 2 9000m 300s 28.57 m/s 7.14 m/s 525m 1.25 x 10-3m/s 2000s 12.5 m/s 3360m 285.71 s Calculator Exercises P3.4 Rounding off 0.11 0.33 0.49 556.49 26.31 23.61 105.66 31.19 EXP Practice 1.5 x 1013 3.58 x 1036 2.28 x 1051 1.2 x 1019 1.54 x 1018 112.5 6.8 x 10-12 1.38 x 10-6 1.81 x 10-7 1.12 x 10-10 8.57 x 10-65 833.33 2.4 x 1021 Average Speed P 5, 6, 7, 8, 9 (a)5 m/s (b)5 m/s (c)12.5 m (d)880 m (e)0.05 s (f)200 s 125 m/s 2 400 m 667 s 192 m/s 780 m 5714 s 120 000 m 55556 s 20 625s (573 h) 1042 m/s 28571 m/s (a)2328 m/s (b)Perth & Dundee (a) 3 m/s 5 s (a) 70 km/h (b)1 h 40 min (c)82.5 km/h (a)480m (b)13.71 s (c) After 15s cheetah is still 5m behind Antelope. Antelope escapes! (a) Donald (b) Mickey’s 82.95 m/s (c) Mickey’s 78.35m/s Donald 77.84 m/s
Goofy 80.00 m/s (d)Goofy – highest average speed Instantaneous Speed P 10, 11, 12 1. (a) 02 m/s (b) 0.15 m/s (c) 7.32 x 10-3s (d) 0.175 m (e) 0.4 m (f) 5.38 x 10-3 s 1.46 m/s A – 8.00 m/s B – 7.69 m/s C – 6.67 m/s D – 6.90 m/s E – 8.00 m/s F – 8.33 m/s F C 105.63 m/s 4 m/s Mixed Speed, Distance, Time Questions P 13. 14 8 m/s Distance between two points e.g. lamp-posts measured using a metre stick Time to travel between two points measured using a stopwatch, = distance/time 5.8 m/s a. 10 km/h b. 2.8 m/s Distance between two points e.g. lamp-posts measured using a metre stick Time to travel between two points measured using a stopwatch, Speed = distance/time 17,000 m 2400 m 8000 s 3409 s = 57 minutes (56.8) 2500 s = 42 minutes (41.7) a. 24.3 m/s b. 28.3 m/s c. No stops between Glasgow and Falkirk. Between Glasgow and Edinburgh the train must stop twice at the station. Use a light gate. When the vehicle passes through the light gate the time the beam is interrupted for is recorded on a timer. The length of the vehicle is measured using a metre stick. Speed = distance/time 0.4 m/s
.a. 0.75 m/s b. 1.49 m/s Speed-Time Graphs P 15 a. AB – constant speed BC – negative acceleration b. AB – acceleration BC – constant speed CD – acceleration c. AB – negative acceleration BC – zero speed CD – acceleration DE – negative acceleration 2. Graphs to be drawn Using Speed-Time Graphs to Calculate Distance P 16, 17, 18, 19 a. 20 m b. 180 m c. 650 m d. 300 m e. 550 m f. 300 m g. 693 m h. 4000 m i. 220 m a. 8 s seeing accident b. 200 m c. 250 m a. 0 – 50 s acceleration 50 – 70 s constant speed 70 – 80 s acceleration 80 – 90 s constant b. 1700 m a. 0 – 20 s constant speed 20 – 30 s negative acceleration 30 – 40 s constant 40 – 50 s negative acceleration 50 – 60 s constant speed 60 – 70 s negative acceleration 70 – 80 s constant speed 80 – 90 s negative acceleration b. 1100 m a. At 10 seconds b. 160m a. 500 m b. deceleration for 560m so that the rocket reaches a point 20m above the Moon and hovers. a. 5s
Gear 4 – 2 m/s2 Gear 3 – 0.75 m/s2 Gear 2 – 2 m/s2 a. 50 – 70 m b. 50 s and 100 s c. 083 m/s2 7. (a) 50 - 70 s (b) 50 s and 100 s (c) m/s2 Acceleration 3 P 36, 37 3 m/s2 22.2 m/s2 2 m/s2 3.5 m/s2 -1200 m/s2 -2.5 m/s2 Measure the velocity at two points, measure the time between the two points. The acceleration is the change in velocity divided by the time taken between the two points. -3.6 m/s2 3.6 m/s 4s 3s 3.4s a. Nissan Micra 1.0s b. Porsche Boxster c. i. 20.7s ii. 15.1 s