Playful Physics

Speed and Velocity


Definition: Speed is the rate of change in distance with time.

My Definition: The rate at which an object covers distance.

Formulas: s= distance traveled/ time traveled

General Info:

  • Scalar
  • Uses distance
  • Can't be negative
  • Its absolute
  • Slope on delta s over delta t


Definition: The speed of something in a given direction.

My definition: Refers to the rate at which an object changes its position.

Formulas: V= Vₒ + at

t= v- vₒ/ a

General Info:

  • Vector
  • Can be negative
  • Uses displacement
  • Has direction
  • Relative
  • Slope on delta x/ delta t graph


1.A hedgehog can run at a speed of up to 72 km/h. How long will it take an ostrich to to run 1.5 km at this top speed?

2. A shooting comet goes 1.73 km downward in 25 s. What is the average velocity of the comet?

3. A seal can swim as fast as 1.7 x 10(squared) km/h. When seal A accelerates 2.67 m/s(squared) so after the displacement is 6.00 x 10 (squared). Calculate the initial velocity, just before the acceleration.

4. A bat flew at a speed of 3.00 x 10 (squared) m/s at an altitude of 12 km, where the speed of sound in air is 3.00 x 10 (squared) m/s. Suppose he accelerated 7.20 m/s (squared) in 25 s to reach the final speed of 3.00 x 10 (squared) m/s. What was his initial speed?