Equations of Motion in Physics

Questions and Answers

What is the formula to find the total distance travelled from a velocity-time graph?

The intercept of the v-t graph

The area above the v-t graph

The slope of the v-t graph

The area underneath the v-t graph (correct)

What is the ratio between the accelerations of an object accelerating from rest in a time t1 and decelerating back to rest in a time t2?

t1^2 : t2^2

t1 : t2^2

t2 : t1

t1 : t2 (correct)

Two objects are moving towards each other with different initial velocities. What is the distance between them?

The sum of the objects’ initial velocities

The product of the objects’ displacements from a shared origin point

The sum of the objects’ displacements from a shared origin point (correct)

The difference between the objects’ displacements from a shared origin point

What is the condition for one object to overtake another?

When the two objects have the same displacement from a certain point Signup and view all the answers

What is the acceleration due to gravity near the Earth’s surface?

9.8 m/s^2 Signup and view all the answers

What is the easiest way to find the area underneath a v-t graph?

By splitting up the shape into triangles and trapezoids Signup and view all the answers

What is the condition for one object to fully pass another?

When the difference in the displacements of both objects is equal to the total length of both objects Signup and view all the answers

What can velocity-time graphs show?

Not only velocity, but acceleration and distance travelled Signup and view all the answers

What is the quantity that links the five important quantities of motion?

Equations of motion Signup and view all the answers

What is the assumption made for objects accelerating from rest and decelerating back to rest?

Constant acceleration Signup and view all the answers

Study Notes

Equations of Motion

Describe motion using 5 quantities: displacement (s), initial velocity (u), final velocity (v), acceleration (a), and time taken (t)
Four equations link these quantities together

Velocity-Time Graphs

Display information about an object's changing speed over time
Can show velocity, acceleration, and distance traveled
Area underneath v-t graph gives total distance traveled
Split shape into triangles and trapezoids to find area easily

Rest to Rest

Object accelerates from rest in time t1 and decelerates back to rest in time t2
Ratio of accelerations equals ratio of times

Two Bodies - Moving Towards Each Other

Distance between two bodies is sum of objects' displacements from shared origin point

Catching Up

Object will overtake another when both have same displacement from a certain point
If one object starts ahead, add distance to equation
If objects start at same point but at different times, add time difference to equation

Passing

One object must cover distance equal to total length of both objects to fully pass the other
Difference in displacements of both objects must equal this distance

Acceleration due to Gravity

Only force acting on an object in free fall is gravity
Gravity causes objects to accelerate towards the ground at constant 9.8 m/s2 near Earth's surface
Steps for a free fall question:
Identify equation of motion with one unknown variable
Substitute known values, including a = -9.8 m/s2
Solve for unknown; for maximum height, speed is 0

Description

Learn about the five quantities used to describe an object's motion with constant acceleration: displacement, initial velocity, final velocity, acceleration, and time taken. Understand how to use velocity-time graphs to display information about an object's changing speed over time.