If a truck goes 30 kilometers in 30 minutes what is the average speed

60 km per hour

Explanation:

if you drive for 30 min and go 30km then if you drive for 60 min(1hr) then you would have driven 60km.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.