revision booklet questions Flashcards
i copy and pasted it in an ai fixed it so idk how good these are (29 cards)
What happens to the chemical energy store in the cyclist’s body as they accelerate?
The chemical energy store decreases and the kinetic energy increases.
Calculate the kinetic energy of a cyclist with a mass of 80 kg and speed of 12 m/s.
K = 5760 J or 5.76 KJ
K = 1/2 × m × v^2 = 1/2 × 80 × 12^2
What is the change in gravitational potential energy of a person with a mass of 45 kg moving through a height of 2.0 m?
U_g = 882.9 J
U_g = m × g × h = 45 × 9.81 × 2
List three factors that affect the kinetic energy of a person on a zip wire.
- Change in vertical height
- Mass / weight
- Speed / velocity
Why is the increase in kinetic energy less than the decrease in gravitational potential energy on the zip wire?
Air resistance or friction of the pulley causes energy to be released as heat.
Why do different people have different speeds at the end of the zip wire?
Different body weights/shapes affect streamlining and air resistance.
How does the distance between particles in steam compare to that in liquid water?
The distance between particles in steam is greater.
How does the density of steam compare to that of liquid water?
The density of steam is less than the density of liquid water.
What is the purpose of surrounding a metal can with layers of newspaper in an insulation experiment?
The newspaper acts as an insulator, keeping heat in the metal can.
How does the internal energy of water change when heated from 20 °C to 25 °C?
The kinetic energy of the water particles increases, raising the thermal energy.
What is the acceleration of a horse that goes from 0 m/s to 9 m/s in 4 seconds?
a = 2.25 m/s²
a = (v_2 - v_1) / t = (9 - 0) / 4
What is the kinetic energy of a pony that is half the mass of a horse with 4000 joules of kinetic energy?
2000 J
Kinetic energy depends on mass.
Calculate the maximum speed of a car that traveled 170 m in 10 seconds.
17 m/s
s = distance / time = 170 / 10
How does the velocity of a rocket change as it moves upwards?
The velocity decreases to zero.
What is the difference between velocity and speed?
Velocity includes direction (vector quantity), while speed does not (scalar quantity).
Which graph shows how the velocity of a rocket changes as it falls from maximum height until it hits the ground?
Graph B.
Describe the motion of a ball between points A and B on a velocity-time graph.
Constant acceleration.
What direction is the ball moving between points C and D on the graph?
Upwards.
How is the velocity of an aircraft different from its speed?
Velocity has direction (vector quantity), while speed is scalar with no direction.
Determine the speed of an aircraft that traveled 12000 m in 50 seconds.
240 m/s
s_av = distance / time = 12000 / 50
Calculate the time taken for an aircraft to decelerate from 250 m/s to 68 m/s at 0.14 m/s².
1300 s
t = (v_2 - v_1) / a = (68 - 250) / -0.14
Calculate the mean force used to stop an aircraft that traveled 2000 m with 140,000,000 J of work done.
70,000 N
F = W / d = 140000000 / 2000
Describe the relationship between the resultant force on a trolley and its acceleration.
As the force increased, the acceleration also increased.
Describe the motion of a remote-controlled car during the first 30 seconds.
The car is accelerating.
