# Physics

Topic: intro into physics

What did I learn in this unit?

1) scalar and vector quantity

scalar is a quantity that is fully described by a magnitude only. It is described by just a single number. Some examples of scalar quantities include speed, volume, mass, temperature, power, energy, and time.

vector is a quantity that has both a magnitude and a direction. Vector quantities are important in the study of motion. Some examples of vector quantities include force, velocity, acceleration, displacement, and momentum

2) speed and velocity

Speed is a scalar quantity that refers to how fast an object is moving.

Velocity is a vector quantity that shows the speed and direction of an object

How do you calculate speed?

Speed can only be calculated if the distance and time is given. The distance the object has covered divided by the time it has taken to cover that certain distance gives the speed, for example if a car travels 20km in 4 hours than the speed is 20km/4 hrs which is 5kmph (kilometers per hour).

velocity canonly be calculated if the displacement and time is given. Displacement is the change in position of an object, displacement also displays the direction the object has moved in for example, if a car goes travels a total distance of 50km but the displacement is only 20km south and the time taken is 2 hours, then the velocity would be 20km/2 hrs which is 10kmph.

What is acceleration?

Acceleration is the rate of change of velocity. Usually, acceleration means the speed is changing, but not always. When an object moves in a circular path at a constant speed, it is still accelerating, because the direction of its velocity is changing.

summary

I learned about what speed and velocity is and how to calculate it. I also learned about what a vector quantity and scalar quantity is, with it’s differences. another sub-topic learned about was acceleration