Fig 3.1 shows the speed-time graph of a firework rocket as it rises and then falls to the ground 2
rocket
moving
upwards
speed
B
time
rocket
moving
downwards
Fig. 3.1
The rocket runs out of fuel at A It reaches its maximum height at B. Al Elt returns to the ground,
(a) (0) Starte the gradient of the graph at B. gradient
.11
00 State why the gradient has this value at B.
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Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

In the sport of parasailing, a person is attached to a rope being pulled by a boat while hanging from a parachute-like sail. a rider is towed at a constant speed by a rope that is at an angle of 15 ∘ from horizontal. the tension in the rope is 1900 n. the force of the sail on the rider is 30∘ from horizontal. what is the weight of the rider? express your answer with the appropriate units.

The softest and hardest minerals are: softest hardest