Balanced and Unbalanced
What happens to an object when forces acting on it are balanced?
moves at a constant speed / stays still
What instrument is commonly used to measure force?
Spring balance
What type of force slows down moving objects?
friction
What is the term for the amount of matter in an object?
mass
What do we call electricity that stays in one place?
static electricity
What do we call forces that cause a change in motion?
unbalanced forces
What unit are forces measured in?
Newtons (N)
Name a surface with high friction.
sandpaper or carpet
What is the term for the force of gravity acting on an object?
weight
What tiny particles are transferred to create static electricity?
electrons
If a book is sitting still on a table, are the forces balanced or unbalanced?
balanced forces
If you pull a spring balance and it reads 5 N, what does that mean?
you are applying a force of 5 newtons
What can you do to reduce friction between two surfaces?
add oil or use smoother surfaces
What unit is mass measured in?
kilograms (kg) or grams (g)
What happens when you rub a balloon on your hair?
the balloon becomes charged and can stick to things
What happens to an object when unbalanced forces act on it?
accelerates (changes speed or direction)
What part of a spring scale stretches when a force is applied?
the spring
Which has more friction: ice or rubber?
rubber
Why is your weight less on the Moon than on Earth?
the Moon has less gravity than Earth
What type of material is likely to create static electricity when rubbed?
an insulator (like plastic or wool)
Name a situation where unbalanced forces cause an object to slow down.
ball rolling on the ground and slowing due to friction, etc.
If two students pull on opposite ends of a spring scale and it stays at zero, what does this tell you about the forces?
forces are balanced
Why do car tyres have tread patterns?
increase friction and prevent slipping
If two objects have the same mass but are on different planets, will their weights be the same?
no; their weights depend on gravity.
What is the sudden discharge of static electricity called?
a spark