Basic
What is a force?
Push or Pull
What is the difference between mass and weight?
Mass is the amount of substance an object possesses
Weight is due to gravity pulling the object down.
(You will be lighter on the moon while keeping your mass)
What is friction?
It is a force that goes in the opposite direction of motion.
How do you calculate extension?
Final length – original length
Name 3 effects of forces.
Change in speed, Change in direction, Change in shape, Move a stationary object, Stop a moving object
What are the 2 factors that will strength of gravity?
Mass and distance between objects
What are the forces acting on a moving ball?
Gravity and Friction
How do we determine which spring is more elastic?
Put the same number of weights on both of the springs. The spring that stretches more is more elastic than the other.
Under what kind of condition will there be no force?
There is no movement although force is applied.
Why is it more tiring to walk up the stairs?
You have to go against gravity when you walk up the stairs.
Name 1 advantage and 1 disadvantage of friction.
Adv: Reduce chance of slipping, allows us to grip things
Disadv: Generate heat, Wear and tear, slow things down
Explain what will happen when an arrow is released from a bow.
The string on the bow exerts an elastic spring force on the arrow, pushing the arrow forward. Due to gravity, the arrow will start to drop and eventually lands on the ground.
What are the 2 factors that will affect the amount of force applied?
Strength/Magnitude of force applied, Direction of force applied
As we climb further up the stairs, we have to go against more gravity. Do you agree with this statement? Explain.
No. Gravity actually weakens as we go further away from the Earth’s core. *Not noticeable so don’t bother trying with a HDB
(This is the reason why a lot of force is needed for a spaceship to lift off.)
In a game of tag-of-war, why are the participants able to hold on to the ropes?
There is friction between their hands and the rope.
What is the difference between Elastic Spring Force and Elastic Potential Energy? (Do not mention spelling and one is a force while the other is an energy)
Elastic Spring Force is a force exerted by an object that has been stretched or compressed.
Elastic Potential Energy is the energy stored in an object that has been stretched or compressed.
(Elastic potential energy is needed to have an Elastic Spring Force)
What are the 2 similarities and 2 differences between gravity and magnetism?
Both can pull and acts from a distance
Gravity: Only pulls and requires the object to have mass
Magnetism: Pulls and pushes and requires a magnet and a magnetic material
What are the 3 ways to reduce friction?
Use of lubricants, Wheels and rollers, Use a smoother surface