P10- Forces and motion 🚙 Flashcards
RECAP: What is Newton’s first law [of motion] ? 🍏
Hint: zero resultant force= object
- Newton’s first law is:
- if the resultant force acting on a stationary object is zero, them the object will remain stationary
- ; if the resultant force acting on a moving object is zero, then the object will continue moving in the same direction, at the same speed [with the same velocity]
What is Newton’s second law of motion? 🍏
Hint: F= ma
- Newton’s second law of motion states:
- the acceleration of an object is proportional, to the resultant force acting on the object.
- ; the acceleration acting on the object is inversely proportional to the mass of the object.
What does it mean that the acceleration of an object, is proportional to the resultant force acting on an object ?
Hint: greater
- the acceleration of an object, being proportional to the resultant force acting on an object means:
- if both objects experience a resultant force, the object with a greater force will have a greater acceleration
What does it mean that the acceleration is inversely proportional to the mass of an object ?
Hint: larger
- if the mass is larger, the object with a larger mass will have a smaller acceleration.
- this is because the acceleration, is inversely proportional to the mass of the object
- Fill in the gaps: cars travel at __m/s on a main road in the UK
- ; however, cars typically travel at __m/s on a motorway
- cars travel at 13m/s on a main road in the UK
- ; however, cars typically travel at 30m/s on a motorway
- Fill in the gaps: to accelerate from a main road to a motorway, it typically involves an acceleration of _m/s.
- but for a typical family car, this would require a force of _____ N
- to accelerate from a main road to a motorway, it typically involves an acceleration of 2m/s
- but for a typical family car, this would require a force of 2000 N
What is the definition of ‘inertia’ ?
Hint: uniform
- inertia is the tendency of an object to stay at rest, or to continue in uniform motion.
- this means, objects will stay still or keep the same motion unless, you apply a resultant force
What is the definition of the term ‘inertial mass’ ?
Hint: velocity
- inertial mass, is the ratio of the force needed to accelerate an object, over the acceleration produced.
- this simply means, inertial mass is a measure of how difficult it is to change the velocity of an object
What does inertial mass mean ?
Hint: measure
- inertial mass, is a measure of how difficult it is to change the velocity of an object
- Fill in the gaps: inertial mass, simply means a ______ of how difficult it is to change the velocity of an object
- an object with a _____ inertial mass, will require a larger force to produce a given ____________ than an object with a smaller inertial mass.
- inertial mass, simply means a measure of how difficult it is to change the velocity of an object
- an object with a large inertial mass, will require a larger force to produce a given acceleration, than an object with a smaller inertial mass.
RECAP: What is Newton’s third law of motion ? 🍏
Hint: exert
- newton’s third law of motion is:
- whenever two objects interact, the forces they exert on each other are equal and opposite.
What’s an example, of Newton’s third law of motion ?
Hint: reverse
- when a car is driving, the wheel exerts a force in the reverse direction on the road.
- ; at the same time, the road exerts a force in the forward direction on the wheel.
- these two forces are equal in magnitude, but opposite in direction.
What is terminal velocity ?
Hint: steady
- terminal velocity, is when an object moves at a steady speed, in a constant direction.
- this is because, the resultant force acting on it is zero.
What does terminal velocity apply to ?
- terminal velocity, also applies to any object falling through a fluid [e.g- water or air]
What happens when a skydiver falls 🪂 ?
Hint: upwards force, balance- why?, terminal velocity
- as a skydiver falls, they experience air resistance with the air particles
- and after some time, the force of air resistance will balance the force, due to gravity.
- the object will then stop accelerating at this point, and it will move at a terminal velocity