Forces
a push or pull on an object
What is a force?
Bonus question - name three forces
two forces are equal in size and opposite in direction
What are balanced forces?
the force that opposes motion
What is friction?
The force that keeps us on the ground
What is gravity?
The unit of force
What is the Newton (N)?
an arrow diagram that shows both direction and magnitude
What is a vector?
when balanced forces act on an object
What stays still/keeps moving at the same speed/direction?
the reasons why luge races are really fast
What is low friction ice, plus going downhill
the amount of matter an object has
what is mass?
Bonus question - what is the unit of mass?
kilograms, metres, seconds
What are the units of mass, distance and time?
the force that pulls objects down
What is weight/gravity?
the forces action on a book resting on a table
What are weight and support?
reason why swimming is a slow sport
Bonus question - what are ways swimmers try to minimise friction in the water?
On Earth, a person has a mass of 60 kg. On the Moon, where gravity is weaker, their mass is this value.
What is 60kg?
The formula for force
According to Newton's First Law, an object at rest will stay at rest unless acted upon by this
What is an unbalanced force?
effect of balanced forces acting on a moving car
What has constant speed/direction?
Bonus question - what are the four main forces acting on a moving car
Bonus, bonus question - what direction are each force acting?
helpful examples of friction
What is walking without slipping, braking a car (or writing with a pencil, gripping objects etc)
Calculate the weight of a 75 kg astronaut on Earth where g = 10 N/kg
What is 750 N?
the forces on an object that has a negative acceleration
What are unbalanced forces where the overall force is opposing the motion?
A 50 N force is applied east and a 30 N force is applied west on the same object. Calculate the net force and state its direction.
What is 20N east?
A 500 kg elevator is pulled upward by a cable with 6000 N of force. If gravity pulls down with 4900 N, calculate the net force and describe the elevator's motion.
What is 1100 N upward?
Friction causes systems to lose energy because of this
What is heat?
A student has a mass of 50 kg on Earth but weighs 80 N on the Moon. Calculate the Moon's gravitational field strength.
What is 1.6 N/kg?
calculate the force on a 2000 g object that accelerates at 5 m/s²
What is 10 N?
Bonus question - what is the full name and title of the scientist who 'discovered' gravity?