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Description
Flashcards by lauren_binney, updated more than 1 year ago
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Created by lauren_binney
over 9 years ago
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| Question | Answer |
| The diagram shows a boat pulling a water skier, The arrow represents the force on the water produced by the engine propeller. This force causes the boat to move. Explain why. | (produces) a force from water on the boat, in the forward direction |
| The force from the boat pulling the water skier forwards will be... | Greater than.. because it needs to overcome resistance forces |
| Why is the component labelled ‘J’ included in the circuit? | To obtain a range of p.d. values../..to increase or decrease current, p.d, voltage or resistance |
| Uranium-235 is used as a fuel in some nuclear reactors. Name one other substance used as a fuel in some nuclear reactors. | plutonium (239) |
| What is meant by thinking distance? | Distance a vehicle travels during the driver’s reaction time. |
| State two factors that affect thinking distance. | Any from: • tiredness • alcohol • drugs • speed of car |
| Applying the brakes of the car causes the temperature of the brakes to increase. Explain why.. | Work done by friction between brakes and the wheel causes a decrease in kinetic energy and increase in thermal energy |
| State and explain the benefit of a hybrid car being fitted with a regenerative braking system. | The battery needs recharging less often which increases the range of the car, and the efficiency of the car is increased. |
| The table gives some information about an atom of iodine-131, complete it | Number of neutrons = 78 |
| Complete the sentence. The number of protons in an atom is called the proton number or the .............................. number. | Atomic |
| The decay of iodine-131 can be represented by the equation below. Complete the equation... | 131 54 |
| Calculate how many days it will take for the count rate from the sample of rainwater to fall to 75 counts per second. Half-life of iodine-131 = 8 days | 32 days |
| In Japan, people likely to be drinking water contaminated with iodine-131 were advised to take tablets containing a non-radioactive isotope of iodine. Suggest why this advice was given. | Limits amount of radioactive iodine that can be absorbed, so reducing risk of cancer of the thyroid |
| What is the difference between an alternating current and a direct current? | a.c. is constantly changing direction d.c. flows in one direction only |
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