1c-Forces, movement, shape and momentum Flashcards
What is Newton’s First Law of Motion?A:
An object will remain at rest or in uniform motion unless acted upon by an external force.
What is Newton’s Second Law of Motion?
A: The acceleration of an object is directly proportional to the force applied and inversely proportional to its mass.
F=Ma
where:
F= force (N)
M= mass (kg)
a= acceleration (m/s²)
What is Newton’s Third Law of Motion?
A: For every action, there is an equal and opposite reaction.
What is the difference between weight and mass?
Mass (kg): The amount of matter in an object (scalar quantity).
Weight (N): The force due to gravity acting on an object’s mass.
W=mg
where:
W= weight (N)
m= mass (kg)
g= gravitational field strength (9.8 N/kg on Earth)
Q: What forces act on a falling object?
1.Gravity pulls the object downward.
2.Air resistance opposes motion.
3.Terminal velocity occurs when air resistance equals weight, resulting in constant velocity.
Q: What factors affect terminal velocity?A:
Mass (heavier objects have a higher terminal velocity)
Shape and surface area (larger surface area increases air resistance)
Density of the fluid (higher density increases drag)
Momentum and Conservation of Momentum
Q: What is momentum?
Momentum is the product of an object’s mass and velocity.
P=mv
where:
p = momentum (kg·m/s)
m= mass (kg)
v= velocity (m/s)
What is the principle of conservation of momentum?
A: In a closed system, total momentum before a collision equals total momentum after a collision.
Q: What is an impulse?
Q: What is an impulse?A: Impulse is the change in momentum, given by:
F x (change in time) = change in p
where change in p is the change in momentum.
What is work done?
A: Work is done when a force moves an object in the direction of the force.
W=fd
W= work done (J)
f= force (N)
d= distance moved in direction of force (m)
What is kinetic energy?
A: The energy an object has due to motion.
What is gravitational potential energy (GPE)?
The energy stored in an object due to its height above the ground.
what is power
A: Power is the rate of energy transfer.
Practical: Investigating Forces and Motion
Investigating Newton’s Second Law
Method: Attach weights to a trolley and measure acceleration using a motion sensor.
Observation: Increased force results in greater acceleration.
Practical: Investigating Forces and Motion
Measuring Terminal Velocity in Fluids
Method: Drop a ball bearing in oil and measure velocity over time.
Observation: The ball reaches terminal velocity when forces balance.
