Forces- half term Flashcards
(20 cards)
What is a force?
A push or a pull.
What happens to an object when the forces acting on it are balanced?
It will either stay still or continue moving at a constant speed in the same direction.
What happens to an object when the forces acting on it are unbalanced?
It will accelerate (speed up, slow down, or change direction).
What is a resultant force?
The single force that has the same effect as all the individual forces acting on an object.
If two forces act on an object in opposite directions, how do you calculate the resultant force?
Subtract the smaller force from the larger force.
What is friction?
A force that opposes motion when two surfaces rub together.
Give one example of when friction is useful.
(e.g., Car tyres on the road, brakes on a bicycle, walking without slipping)
Give one example of when friction is unhelpful.
(e.g., Wears out moving parts, makes it harder to slide objects, causes heat)
What does a flat horizontal line on a distance-time graph tell you about the object’s motion?
The object is stationary (not moving).
What does a sloping straight line on a distance-time graph tell you about the object’s motion?
The object is moving at a constant speed.
How do you calculate the speed of an object from a distance-time graph?
Calculate the gradient (steepness) of the line: speed = distance / time.
What is the word equation that links distance, speed, and time?
Distance = Speed × Time
If a car travels at a speed of 10 m/s for 5 seconds, how far has it travelled?
50 meters (10 m/s × 5 s = 50 m)
What is weight?
The force of gravity acting on an object.
What is the unit for weight?
Newtons (N)
What is the word equation that links weight, mass, and gravitational field strength?
Weight = Mass × Gravitational Field Strength
If an object has a mass of 2 kg and the gravitational field strength is 10 N/kg, what is its weight?
20 Newtons (2 kg × 10 N/kg = 20 N)
What equipment would you use to measure the extension of a spring in an experiment?
A ruler or a metre rule.
What would you plot on the axes of a graph for a Hooke’s Law experiment (stretching a spring)?
Force (or weight) on the y-axis and Extension on the x-axis.
What did Robert Hooke’s Law discover about stretching a spring?
The extension of a spring is directly proportional to the force applied to it (up to the elastic limit). In simpler terms, if you double the force, you double the stretch.
