SUVAT

Key Stage 4

Meaning

A suvat is an equation of motion for an object.

About suvat Equations

suvat equations can be used to find one of these variables:

• Displacement (s) - How far an object is from its starting position.
• Initial Velocity (u) - The velocity of an object at the start.
• Final Velocity (v) - The velocity of an object at the end.
• Acceleration (a) - The rate of change of velocity.
• Time (t) - The time taken between to points on a journey.

Equations

\(v=\frac{s}{t}\)

\(a=\frac{v-u}{t}\)

\(v^2=u^2 + 2as\)

Example Calculations

Using v, s and t

A wave travels 1000m in a time of 12.5s. Calculate the magnitude of the velocity of the wave correct to two significant figures.	The Moon is approximately 390,000km away from the Earth. A Radio Wave travels at 300,000,000m/s from The Moon to the Earth. Calculate the time taken by the Radio Wave to reach Earth correct to two significant figures.	An alpha particle travels for 4.0ns at a velocity of 15,000,000m/s before colliding with an air molecule. Calculate the displacement of the alpha particle from the start to the end of its journey correct to two significant figures.
1. State the known quantities s = 1000m t = 12.5s	1. State the known quantities s = 390,000km = 390,000,000m v = 300,000,000m/s	1. State the known quantities v = 15,000,000m/s t = 4.0ns = 4.0 x 10-9m
2. Substitute the numbers and evaluate. \(v = \frac{s}{t}\) \(v = \frac{1000}{12.5}\) \(v = 80m/s\)	2. Substitute the numbers and evaluate. \(v = \frac{s}{t}\) \(300000000 = \frac{390000000}{t}\)	2. Substitute the numbers and evaluate. \(v = \frac{s}{t}\) \(15000000 = \frac{s}{4.0 \times 10^{-9}}\)
3. Rearrange the equation and solve. Already solved.	3. Rearrange the equation and solve. \(300000000 = \frac{390000000}{t}\) \(300000000t = 390000000\) \(t = \frac{390000000}{300000000}\) \(t = 1.3s\)	3. Rearrange the equation and solve. \(15000000 = \frac{s}{4.0 \times 10^{-9}}\) \(s = 15000000 \times 4.0 \times 10^{-9}\) \(s = 0.060m\)