Forces General
A force can be defined as....
A push or pull or twist
Is air resistance a contact or non-contact force?
Contact
Define gravity.
An attractive force between any two objects that have mass.
Explain net force.
The total (overall) force acting on an object.
You can measure the length of a desk using a...
Ruler/measuring tape
The units force is measured in is.....
Newtons
Define contact force.
Any force that can only occur when 2 objects are touching.
Is gravity a contact or non-contact force? Is it a push or a pull force?
Non-contact
Pull
Explain the difference between balanced and unbalanced forces.
Balanced forces = Equal in size but opposite in direction. The net force of balanced forces is zero. Objects acted upon by balanced forces stay at rest or move at a constant velocity.
Unbalanced forces = Unequal in siza and may or may not act in the same direction. Net force is more than zero. Objects acted upon by balanced forces will change in speed, shape or direction.
You can measure forces using a...
Spring balance
Name 3 effects of forces.
Start motion, stop motion, speed up, slow down, change direction.
Name three contact forces.
Applied, friction, air resistance, buoyancy, elastic, tension.
Name 3 non-contact forces.
Gravity, magnetic, static electricity
Explain what would happen if the air resistance of a falling object becomes balanced with its weight.
If the forces are balanced on a falling object, it will fall at a constant speed in a constant direction.
What is a hypothesis?
An educated guess/prediction.
Explain how you could get a book resting on a ramp to begin to move.
The force that makes a boat float is called...
Upthrust or buoyancy
Explain the difference between mass and weight
Mass is the amount of matter in an object and remains constant regardless of location. Weight, on the other hand, is the force exerted on an object due to gravity, and it can change depending on the gravitational field
A object is being pushed to the right with 10N of applied force. There is 5N of friction acting on the object. Calculate the net force.
10 - 5 = 5N Right
A variable in an experiment that is deliberately changed by the scientist is called a/an...
Independent variable
Forces can be represented by an arrow. What characteristics should you consider when drawing your arrow?
Size and direction.
Explain why an object would take longer to slide down a surface of sandpaper compared to a surface of smooth, waxed wood.
Smooth, waxed wood has less friction.
Would it be easier for a rocket to take off from the Earth or the moon? Justify your anser.
The moon because it has less mass. Therefore, it has a weaker gravitational field strength.
A car is driving at a constant speed and direction. The force pushing the car forward is thrust, while the force acting in the opposite direction is drag.
a. Draw a force diagram to represent the forces acting on the car if it speeds up.
b. Explain whether the forces acting on the car as it speeds up are balanced or unbalanced.
a. Bigger thrust arrow, smaller drag arrow.
b. The forces acting on the car as it speeds up are unbalanced.
Liam and Khalda are investigating what could happen to a passenger in a car crash. A marble is carefully balanced on a model car. The model is then released so it can roll down a ramp at different angles to change its speed. When the trolley hits the bottom of the ramp and stops suddenly, the marble flies off the cart. The distance the marble travels is measured using a ruler.
What is the independent variable? What is the dependent variable?
Independent: Angle of the ramp (speed of the trolley)
Dependent: Distance the marble travels measured using a ruler.