1. You are roller blading down a hill, acceleratingfrom rest at 1.5ms-2. Sketch your velocity-time graph up to the moment you crash 10 seconds later. Show the maximum velocity you reach just before crashing. Calculate your distance travelled down the hill. ( 75 m )
2. Suppose that when you play netball or basketball,you can throw the ball at a speed of 10ms-1 during a pass. What speed is this in kmh-1? Think carefully about such a fast pass and guess the time it is in your hands during the throw. Hence make a reasonable estimation about the acceleration you give it. (36 kmh-1 )
3. You are learning to drive a car. Sensibly you are out in a paddock in your sister's heap of a Corolla with a bunch of "friends". Interpret your vel-time graph below, calculating your accelerations and the maximum distance you travel. ( In which section were you "kangaroo-hopping"and where did you change to second? ) ( 77.5 m )
4. It is entirely possible to break a bone jumping from the desk at school. Suppose the desk is 80cm high and you jump off to fall at 9.8ms-2. For how long are you in the air ? What is your speed immediately before you hit the ground? ( 0.4s , 3.96 ms-1)
Let's suppose you are stupid enough to keep your knees rigid (with fear) as you touch the ground and you subsequently stop in 0.1s. To what acceleration do you subject your body ? ( 39.6 ms-2)
Why is the "sport" of bungee jumping relatively safe?
5. Sketch a displacement-time graph for your bus between stops.
6. Suppose you throw a rock almost straight up as hard as you can at a speed of 15ms-1.If the acceleration due to gravity is 9.8ms-2, for how long is it in the air ( ignoring the air) and how high does it go?
( 3.1s , 11.5 m )
7. You are on a bike moving at 10ms-1 when you start going up a straight ramp inclined at 150. We can calculate your theoretical acceleration on the ramp by the formula a= 9.8 sin 150 in ms-2. Without pedalling, how far should you go up the ramp? (19.7 m)
6. A high diver leaps upwards at 2ms-1 from the 10m board. How long does it take for her to reach the water? (1.65s)
Why is it important to make a very straight,deep diving entry? How is this reflected in the splash made?