Forces And Motion Test Flashcards
Define speed and state possible units
Speed is the distance covered per unit time. The units are normally; speed m/s, distance m and time s.
Calculate speed
Speed is calculated by this formula:
Speed= distance/ time
/= over (which means divided by)
Complete an investigation to find the speed at which someone is travelling
Eg1. A car covers 100m in 10s. What is the speed of the car?
S=d/t
= 100/10=10km/h
= 10 mps
Find distance and speed from a distance time graph
Steps:
1. Draw the triangle.
2. Find the length of each side of the triangle.
3. Divide the height by the width.
4. Give your answer units.
Draw distance time graphs
Find the triangle
Define acceleration and state the units
Acceleration is the rate of change in velocity. Acceleration’s units are m/s squared.
Define velocity
Velocity describes the speed at which something is travelling and the direction.
What is the equation for acceleration?
Acceleration= change in velocity
—————————-
Time
A= v-u
——- V= final velocity
t U= initial velocity
Describe how force can be measured and state the unit
All forces are measured in Newtons. Some are measured with a Newton meter.
Define weight and mass and state their units
Mass is the amount of matter an object has. It is measured in kg. Weight is the force of an object due to mass and gravitational acceleration. As it is a force, it is measured in Newtons.
Describe the difference between weight and mass
Weight is measured in Newtons(force) and mass is in kg. Weight is the force on the object due to mass but mass is just the amount of matter.
State Newton’s Laws of motion
1st Law: unbalanced forces cause acceleration
2nd Law: describes how an object’s mass affects how much force is needed to accelerate it.
3rd Law: all forces come in pairs
Describe the influence of balanced and unbalanced forces on an object
If forces are balanced, an object will remain stationary or continue to move at a constant speed. Unbalanced forces cause objects to accelerate.
What is the gravity equation?
Weight= mass x gravitational field strength
W= m x g
What is a contact force? Provide examples.
Contact forces act directly on an object. The contact forces are weight, friction, air resistance, water resistance, upthrust, tension and reaction.
