Method 3 Given Multiple Speeds for Different Amounts of Time
- Assess what information you are given. Use this method if you know:
- Set up the formula for average speed.
- Determine the total distance.
- Determine the total time.
- Divide the total distance traveled by the total time spent traveling.
How do we calculate for speed?
For a body moving at a uniform velocity you can calculate the speed by dividing the distance traveled by the amount of time it took, for example one mile in 1/2 hour would give you 2 miles per hour. If the velocity is non-uniform all you can say is what the average speed is. Same calculation.
An easy way to remember the distance, speed and time equations is to put the letters into a triangle. The triangles will help you remember these 3 rules: Distance = Speed x Time. Time = Distance/Speed.
The average speed of an object is the total distance traveled by the object divided by the elapsed time to cover that distance. It's a scalar quantity which means it is defined only by magnitude. A related concept, average velocity, is a vector quantity.
To calculate displacement, simply draw a vector from your starting point to your final position and solve for the length of this line. If your starting and ending position are the same, like your circular 5K route, then your displacement is 0. In physics, displacement is represented by Δs.
The work is calculated by multiplying the force by the amount of movement of an object (W = F * d). A force of 10 newtons, that moves an object 3 meters, does 30 n-m of work. A newton-meter is the same thing as a joule, so the units for work are the same as those for energy – joules.
Method 1 Finding Average Velocity
- Find average velocity when acceleration is constant.
- Set up an equation with position and time instead.
- Find the distance between the start and end points.
- Calculate the change in time.
- Divide the total displacement by the total time.
- Solve problems in two dimensions.
To find the unit rate, divide the numerator and denominator of the given rate by the denominator of the given rate. So in this case, divide the numerator and denominator of 70/5 by 5, to get 14/1, or 14 students per class, which is the unit rate.
Divide the distance by the time. Plug the two values into the formula and divide. This will give you the speed. If the units on the graph were listed in units other than meters per second, you will need to convert the units to find the speed in meters per second.
The SI unit of time is the second. The SI unit of speed and velocity is the ratio of two — the meter per second. This unit is only rarely used outside scientific and academic circles. Most people on this planet measure speeds in kilometer per hour (km/h or sometimes kph).
Average Velocity, General. The average speed of an object is defined as the distance traveled divided by the time elapsed. Velocity is a vector quantity, and average velocity can be defined as the displacement divided by the time.
The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count.
Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is commonly used.
The formula for force says force is equal to mass (m) multiplied by acceleration (a). If you have any two of the three variables, you can solve for the third. Force is measured in Newtons (N), mass in kilograms (kg), and acceleration in meters per second squared ( m/s2 ).
Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called "speed", being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s) or as the SI base unit of (m⋅s−1).
Speed is the distance traveled by an object where as, velocity is distance traveled by an object per unit time in a particular direction. Speed is a scalar quantity where as velocity is a vector quantity.
The easiest way to do these calculations is to work out the difference between the final velocity and the initial velocity, then divide by the time taken.
- For example, a car accelerates from 25 m/s to 35 m/s in 5 s.
- Its velocity changes by 10 m/s (35 – 25)
- So its acceleration is 10 ÷ 5 = 2 m/s2
Speed is the rate at which an object's position changes, measured in meters per second. The equation for speed is simple: distance divided by time. If the speed of the object is constant, you'll be able to calculate that constant speed. If the speed is changing, you can find the average speed during the motion.
In physics, escape velocity is the minimum speed needed for an object to escape from the gravitational influence of a massive body. The escape velocity from Earth is about 11.186 km/s (6.951 mi/s; 40,270 km/h; 25,020 mph) at the surface.
Average speed is a rate. In kinematics, a rate is always a quantity divided by the time taken to get that quantity (the elapsed time). Since average speed is the rate position changes, average speed = distance traveled/time taken.