Podcast
Questions and Answers
A crane lifts a $50 \text{ kg}$ mass to a height of $10 \text{ m}$ in $5 \text{ s}$. How does the gravitational potential energy (GPE) change, and what is the average rate of change of GPE with respect to time during this process? Assume $g = 9.8 \text{ N/kg}$.
A crane lifts a $50 \text{ kg}$ mass to a height of $10 \text{ m}$ in $5 \text{ s}$. How does the gravitational potential energy (GPE) change, and what is the average rate of change of GPE with respect to time during this process? Assume $g = 9.8 \text{ N/kg}$.
- GPE decreases by $500 \text{ J}$, average rate of change is $-100 \text{ W}$.
- GPE decreases by $4900 \text{ J}$, average rate of change is $-980 \text{ W}$.
- GPE increases by $500 \text{ J}$, average rate of change is $100 \text{ W}$.
- GPE increases by $4900 \text{ J}$, average rate of change is $980 \text{ W}$. (correct)
A car with a mass of $1000 \text{ kg}$ accelerates from $10 \text{ m/s}$ to $20 \text{ m/s}$. What is the change in kinetic energy?
A car with a mass of $1000 \text{ kg}$ accelerates from $10 \text{ m/s}$ to $20 \text{ m/s}$. What is the change in kinetic energy?
- $\text{200,000 J}$
- $\text{50,000 J}$
- $\text{150,000 J}$ (correct)
- $\text{250,000 J}$
In a circuit with a constant voltage source, what happens to the current if the resistance is doubled?
In a circuit with a constant voltage source, what happens to the current if the resistance is doubled?
- The current becomes four times larger.
- The current remains the same.
- The current doubles.
- The current is halved. (correct)
A circuit has a voltage of $12 \text{ V}$ and a resistance of $4 \Omega$. What is the current in the circuit?
A circuit has a voltage of $12 \text{ V}$ and a resistance of $4 \Omega$. What is the current in the circuit?
Which of the following statements correctly describes the arrangement and motion of particles in a liquid?
Which of the following statements correctly describes the arrangement and motion of particles in a liquid?
An atom has 6 protons and 8 neutrons. What is its mass number?
An atom has 6 protons and 8 neutrons. What is its mass number?
Uranium-238 (²³⁸U) undergoes alpha decay. What are the mass number and atomic number of the resulting nucleus?
Uranium-238 (²³⁸U) undergoes alpha decay. What are the mass number and atomic number of the resulting nucleus?
A radioactive isotope has a half-life of 10 years. If a sample initially contains 1000 atoms, approximately how many atoms of the isotope will remain after 30 years?
A radioactive isotope has a half-life of 10 years. If a sample initially contains 1000 atoms, approximately how many atoms of the isotope will remain after 30 years?
Which type of radiation poses the greatest risk if ingested or inhaled?
Which type of radiation poses the greatest risk if ingested or inhaled?
A material can block beta particles but not gamma rays. Which statement is correct?
A material can block beta particles but not gamma rays. Which statement is correct?
Flashcards
Gravitational Potential Energy (GPE)
Gravitational Potential Energy (GPE)
Energy due to an object's height and mass.
Kinetic Energy (KE)
Kinetic Energy (KE)
Energy due to an object's motion.
Energy Dissipation
Energy Dissipation
Energy is 'spread out', often as heat, due to friction or air resistance.
Current (I)
Current (I)
Signup and view all the flashcards
Potential Difference (V)
Potential Difference (V)
Signup and view all the flashcards
Resistance (R)
Resistance (R)
Signup and view all the flashcards
Isotopes
Isotopes
Signup and view all the flashcards
Half-life
Half-life
Signup and view all the flashcards
Health Risks of Nuclear Radiation
Health Risks of Nuclear Radiation
Signup and view all the flashcards
Gamma Radiation
Gamma Radiation
Signup and view all the flashcards
Study Notes
- Study notes from provided scientific information
Energy
- Gravitational Potential Energy (GPE) is calculated using: GPE = mgh, where m is mass in kg, g is gravitational field strength in N/kg, and h is height in meters.
- GPE increases when an object is lifted and decreases when it falls.
- Kinetic Energy (KE) is calculated using: KE = ½ mv², where m is mass in kg and v is velocity in m/s.
- KE increases as speed increases.
- Energy dissipates due to friction and air resistance, typically as heat.
- Lubrication and streamlining reduce energy dissipation.
Electricity
- Current (I) is measured in amperes (A) using an ammeter in series.
- Potential Difference (V) is measured in volts (V) using a voltmeter in parallel.
- Resistance (R) is measured in ohms (Ω) and can be calculated using Ohm’s Law.
- Increasing resistance reduces current for a fixed voltage.
- Ohm’s Law: V = IR, where V is voltage in volts, I is current in amperes, and R is resistance in ohms.
- For an ohmic conductor at a constant temperature, voltage and current are directly proportional.
- Conventional current flows from positive to negative.
- Electrons flow from negative to positive.
- Potential difference (voltage) is energy per unit charge.
The Particle Model of Matter
- Solids have tightly packed particles that vibrate in place, giving them a fixed shape and volume.
- Liquids have particles close together that can move past each other, resulting in a fixed volume but no fixed shape.
- Gases have particles far apart in random motion, with no fixed shape or volume, and are compressible.
Atomic Structure
- Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
- Alpha decay reduces mass number by 4 and atomic number by 2.
- Beta decay converts a neutron into a proton, increasing the atomic number by 1.
- Half-life is the time it takes for half of the radioactive nuclei in a sample to decay.
- Half-life can be determined from a decay curve by repeatedly halving the initial value.
- Radioactive decay is an exponential process.
- Nuclear radiation causes ionization, potentially leading to cell damage and cancer.
- Alpha radiation is dangerous if ingested or inhaled.
- Beta and gamma radiation can penetrate the body and damage internal cells.
- Alpha radiation is stopped by paper.
- Beta radiation is stopped by aluminum.
- Gamma radiation is stopped by thick lead.
- Alpha radiation is the most ionizing.
- Gamma radiation is the most penetrating.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
