PS Test 5 (7th) 21-22

What is speed?

• the distance an object travels in a period of time

• the time an object travels in a period of distance

• none of the above

What is the formula of speed ?

•  $speed=\frac{dista\eta ce}{time}$  

•  $speed\ =\frac{time}{dista\eta ce}$  

• none of the above

Which of these are units of distance?

• km, m, cm, mm

• day, h, min, sec

• kg, g, mg, ng

Which one of these are units of time?

• km, m, cm, mm

• kg, g, mg, ng

• day, h, min, sec

which one are units of speed ?

• km/h , m/s

• kg, lb, ton

• m², km²

The speed of most moving objects is changing constantly

• True

• False

An object is moving if

• the distance to a reference point is changing

• the distance to a reference point is NOT changing

• none of the above

Reference points have to be

• stationary objects

• moving objects

• none of the above

Is the skydiver moving relative to the airplane? Is it moving relative to the ground?

Explain the difference between distance and displacement