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Questions and Answers
What is the size of the upward force acting on the gymnast from the bar compared to the downward force they exert?
What is the size of the upward force acting on the gymnast from the bar compared to the downward force they exert?
Why is the weight of the gymnast represented by an arrow in diagrams?
Why is the weight of the gymnast represented by an arrow in diagrams?
What is the name given to the point from which the weight of the gymnast acts in a diagram?
What is the name given to the point from which the weight of the gymnast acts in a diagram?
What is the weight of a gymnast with a mass of 45 kg in a gravitational field strength of 9.8 N/kg?
What is the weight of a gymnast with a mass of 45 kg in a gravitational field strength of 9.8 N/kg?
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As the gymnast swings from one bar to another, how do the gravitational potential energy and the kinetic energy change?
As the gymnast swings from one bar to another, how do the gravitational potential energy and the kinetic energy change?
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What is the gravitational potential energy (g.p.e.) of the girl at the top of the ramp if her height is 5 meters?
What is the gravitational potential energy (g.p.e.) of the girl at the top of the ramp if her height is 5 meters?
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What is the kinetic energy of the girl at the bottom of the ramp with a speed of 7 m/s?
What is the kinetic energy of the girl at the bottom of the ramp with a speed of 7 m/s?
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Which factor does NOT contribute to the energy loss when the girl moves from the top to the bottom of the ramp?
Which factor does NOT contribute to the energy loss when the girl moves from the top to the bottom of the ramp?
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What does lubricating the wheels of the skateboard primarily accomplish?
What does lubricating the wheels of the skateboard primarily accomplish?
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Which statement best explains the relationship between gravitational potential energy and kinetic energy in this scenario?
Which statement best explains the relationship between gravitational potential energy and kinetic energy in this scenario?
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What is the power output of one wind turbine if the total output of the wind farm is 19.6 MW?
What is the power output of one wind turbine if the total output of the wind farm is 19.6 MW?
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Which of the following is a reason people might not like having wind turbines near their homes?
Which of the following is a reason people might not like having wind turbines near their homes?
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The total amount of electricity generated from various energy resources in the UK was the same in which years?
The total amount of electricity generated from various energy resources in the UK was the same in which years?
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What can be a potential environmental impact of increasing renewable energy resources?
What can be a potential environmental impact of increasing renewable energy resources?
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How many reasons are requested for why people might dislike wind turbines near their homes?
How many reasons are requested for why people might dislike wind turbines near their homes?
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Which statement is true about the wind farm mentioned?
Which statement is true about the wind farm mentioned?
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What aspect related to wind turbines could be a misconception among the public?
What aspect related to wind turbines could be a misconception among the public?
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What is the main purpose of the electrical heating element in the glass window mentioned?
What is the main purpose of the electrical heating element in the glass window mentioned?
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What is the specific heat capacity of castor oil?
What is the specific heat capacity of castor oil?
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Which two energy resources listed are renewable?
Which two energy resources listed are renewable?
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What is the mass of the castor oil used in the calculation?
What is the mass of the castor oil used in the calculation?
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Which unit is used to measure thermal energy in the context provided?
Which unit is used to measure thermal energy in the context provided?
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Which statement correctly describes a reliable energy resource?
Which statement correctly describes a reliable energy resource?
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Calculate the change in thermal energy if the mean change in temperature is 20 °C. Choose the correct value using the provided parameters.
Calculate the change in thermal energy if the mean change in temperature is 20 °C. Choose the correct value using the provided parameters.
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What does the mean change in temperature represent in the context of thermal energy?
What does the mean change in temperature represent in the context of thermal energy?
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Which of the following is NOT a characteristic of non-renewable energy resources?
Which of the following is NOT a characteristic of non-renewable energy resources?
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What happens to the elastic potential energy as the athlete transitions from position B to position C?
What happens to the elastic potential energy as the athlete transitions from position B to position C?
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What is the change in gravitational potential energy of the athlete between positions C and D?
What is the change in gravitational potential energy of the athlete between positions C and D?
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What is the correct unit to express the speed of the athlete at position D?
What is the correct unit to express the speed of the athlete at position D?
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Why does the athlete have less energy at position E compared to position A?
Why does the athlete have less energy at position E compared to position A?
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What is the kinetic energy of the athlete at position D?
What is the kinetic energy of the athlete at position D?
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What will be the speed of the athlete at position D, if their kinetic energy is 1600 J and mass is 50 kg?
What will be the speed of the athlete at position D, if their kinetic energy is 1600 J and mass is 50 kg?
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If the gravitational field strength is 9.8 N/kg, what is the gravitational potential energy change for an athlete of 50 kg falling a height of 3.0 m?
If the gravitational field strength is 9.8 N/kg, what is the gravitational potential energy change for an athlete of 50 kg falling a height of 3.0 m?
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What does the decrease in elastic potential energy between positions B and C imply?
What does the decrease in elastic potential energy between positions B and C imply?
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What happens to the energy stores in the car as it moves?
What happens to the energy stores in the car as it moves?
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What is the correct equation that relates kinetic energy, mass, and speed?
What is the correct equation that relates kinetic energy, mass, and speed?
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If the mass of the car is 800 g, how should it be represented in kilograms for calculations?
If the mass of the car is 800 g, how should it be represented in kilograms for calculations?
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What is the maximum kinetic energy of the car traveling at 12 m/s?
What is the maximum kinetic energy of the car traveling at 12 m/s?
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Why does a more efficient motor lead to a higher top speed for the car?
Why does a more efficient motor lead to a higher top speed for the car?
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Which of the following statements is true regarding the transformation of energy in the car's battery during motion?
Which of the following statements is true regarding the transformation of energy in the car's battery during motion?
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How can we define efficiency in the context of the car’s performance?
How can we define efficiency in the context of the car’s performance?
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What would likely happen if the efficiency of the motor decreases?
What would likely happen if the efficiency of the motor decreases?
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Study Notes
Lift System
- A lift system uses a cable connected to a counterweight.
- An electric motor powers the lift.
- The counterweight moves down the same distance as the lift moves up.
- The gravitational potential energy of the counterweight decreases as it moves down.
Gravitational Potential Energy Calculation
- Gravitational potential energy (GPE) = mass × gravitational field strength × height
- Use the provided mass and gravitational field strength to calculate any change in gravitational potential energy.
Energy Transformation in a Lift
- Friction between the brakes and the cable causes a decrease in the lift's kinetic energy, leading to an increase in the brakes' internal energy.
- Different factors, such as the distance travelled or the weight of passengers, affect the energy transferred by the motor.
Elastic Potential Energy Calculation
- Elastic potential energy = 0.5 × spring constant × (extension)2
- Use this equation to calculate the elastic potential energy of the cable.
- The mass of the lift and counterweight stretches the cable, acting like a spring.
Lift System Efficiency
- A lift system using a counterweight is more efficient than a lift system that does not use a counterweight.
Trampoline
- A trampoline uses stretched springs to support the sheet of material.
- The child's energy changes from potential to kinetic as the child moves from position A to position B.
- Springs store elastic potential energy, while surroundings store internal energy.
- Calculate the extension of a trampoline spring using its elastic potential energy.
Far-Lepping
- Far-lepping involves an athlete using a long pole to cross a river.
- The athlete's energy changes between kinetic and gravitational potential as they move between positions.
- Calculate the change in gravitational potential energy of the athlete.
- Find the athlete's speed at a particular point given their kinetic energy.
Wood-Fired Hot Tub
- Wood is a renewable biofuel.
- Environmental effects of using wood as energy include deforestation and air pollution.
- Wood, pipe, and water's energy stores change as water heats up.
Eco-House
- Solar panels and wind turbines are renewable energy resources.
- These resources are replenished as they are used and don't produce greenhouse gases.
- Biomass, nuclear, and natural gas are other energy resources.
Bicycle Ride
- The gradient of a distance-time graph is the speed of the bicycle.
- Air resistance and friction are non-contact forces acting on a moving bicycle.
- Calculate the work done using the equation: work done = force × distance.
- As the bicycle moves, work is done against frictional forces, and there's no change in energy in the cyclist's kinetic/gravitational potential energy store.
Gymnast on Parallel Bars
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The upward force acting on a gymnast is the same size as their downward force on the bar.
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Weight is a vector.
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The point from which the weight acts is called the centre of mass/gravity.
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Calculate the weight of the gymnast using the equation weight = mass × gravitational field strength.
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Describe how the gymnast's gravitational potential energy and kinetic energy change as they swing between bars.
Toaster
- The earth wire in a three-core cable is used as a safety measure to prevent the metal case from becoming live in case of a fault.
- Different wires have different colours of insulation, live (brown), neutral (or white), and earth.
- Calculate the energy transferred by the toaster using the equation energy = power × time.
- When bread is in a toaster, a spring inside stores elastic potential energy; the toast moves upwards, generating kinetic energy as its speed increases.
Other Topics
- Calculate the elastic potential energy using the equation: elastic potential energy = 0.5 × spring constant × (extension)2.
- The total energy transferred by the child is a quantity of an equals to the work done by the child.
- Explain why a kangaroo can jump higher as its speed increases.
- Some chip pieces in a deep fryer undergo a physical change and become steam due to heat. No chemicals are involved in this physical change; and it can be reversed when chilled.
- Describe how particles in ice cream vibrate about fixed positions.
- Explain why a can-chiller cools drinks using conduction to transfer energy to the surroundings, and the cooling fins are dark/black, which helps them radiate quicker.
- Describe different processes of energy transfer from hot water in a cup to the surroundings.
- Explain why the temperature of the water doesn't fall below room temperature as the can chiller transfers heat into its surroundings
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Description
Test your understanding of forces and energy concepts in physics with this quiz. You'll explore topics like gravitational potential energy, kinetic energy, and the forces acting on a gymnast. Ideal for students looking to reinforce their knowledge in classical mechanics.
