Difference between revisions of "Velocity"
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: The [[velocity]] of an [[object]] can change while the [[speed]] remains constant. | : The [[velocity]] of an [[object]] can change while the [[speed]] remains constant. | ||
| − | === | + | ===Equation=== |
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[[Velocity]] = (Displacement) / (time) | [[Velocity]] = (Displacement) / (time) | ||
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<math>t</math> = The [[time]] taken between the two points. | <math>t</math> = The [[time]] taken between the two points. | ||
| − | === | + | ===Example Calculations=== |
{| class="wikitable" | {| class="wikitable" | ||
| style="height:20px; width:200px; text-align:center;" |A [[wave]] travels 1000m in a time of 12.5s. Calculate the [[magnitude]] of the [[velocity]] of the [[wave]] correct to two [[Significant Figures|significant figures]]. | | style="height:20px; width:200px; text-align:center;" |A [[wave]] travels 1000m in a time of 12.5s. Calculate the [[magnitude]] of the [[velocity]] of the [[wave]] correct to two [[Significant Figures|significant figures]]. | ||
Revision as of 09:20, 12 February 2019
Contents
Key Stage 3
Meaning
Velocity is very similar to speed but it includes the direction an object is moving.
Key Stage 4
Meaning
Velocity is a vector quantity describing the speed and direction of a moving object.
About Velocity
- Velocity is a scalar because it has magnitude and direction.
- The SI Unit for the magnitude of velocity is metres per second (m/s).
- Velocity is different from its scalar counterpart 'speed' because speed does not include the direction of travel.
- The velocity of an object can change while the speed remains constant.
Equation
Velocity = (Displacement) / (time)
\(v = \frac{x}{t}\)
Where\[v\] = Velocity of the object.
\(x\) = The displacement between the starting point and end point of a journey.
\(t\) = The time taken between the two points.
Example Calculations
| 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. It takes a Radio Wave 1.3 seconds to travel that distance. Calculate the magnitude of the velocity of the Radio Wave correct to two significant figures. | An alpha particle can travels around 6cm from a source taking 4.0ns before colliding with an air molecule. Calculate the magnitude of its velocity on this journey correct to two significant figures. |
| 1. State the known quantities
x = 1000m t = 12.5s |
1. State the known quantities
x = 390,000km = 390,000,000m t = 1.3s |
1. State the known quantities
x = 6cm = 0.06m t = 4.0ns = 4.0 x 10-9m |
| 2. Substitute the numbers into the equation and solve.
\(v = \frac{x}{t}\) \(v = \frac{1000}{12.5}\) \(v = 80m/s\) |
2. Substitute the numbers into the equation and solve.
\(v = \frac{x}{t}\) \(v = \frac{390000000}{1.3}\) \(v = 300,000,000m/s\) |
2. Substitute the numbers into the equation and solve.
\(v = \frac{x}{t}\) \(v = \frac{0.06}{4.0 \times 10^{-9}}\) \(v = 15,000,000m/s\) |