Motion in a straight line

You want a projectile to fly as far as possible, at which angle should you launch it? We'll start with formulas for the initial velocity.

Figuring out the horizontal displacement for a projectile launched at an angle.

How to solve for the horizontal displacement when the projectile starts with a horizontal initial velocity. We also explain common mistakes people make when doing horizontally launched projectile problems.

Visualising position, velocity and acceleration in two-dimensions for projectile motion.

Determining how fast something will be traveling upon impact when it is released from a given height. 

Plotting projectile displacement, acceleration, and velocity as a function of time.

Viewing g as the value of Earth's gravitational field near the surface rather than the acceleration due to gravity near Earth's surface for an object in freefall.

Basics of gravity and the Law of Universal Gravitation.

Understanding why distance is area under velocity-time line.

Instantaneous speed is a measurement of how fast an object is moving at that particular moment. Instantaneous velocity is a vector quantity that includes both the speed and the direction in which the object is moving. Learn how to find an object’s instantaneous speed or velocity in three ways - by using calculus, by looking at the slope of a given point on a graph of an object’s rate vs. time, or by using kinematic formulas if the object’s acceleration is constant.