.A truck moves at a constant speed of 90km / h for a straight highway. 1. )How far does it travel in 2 hours? 2. )How far does it travel per second? 3.) How long will it take to travel 10km?

1) 180 km

2) 25 m

3) 6 min 40 sec

Explanation:

1) Distance = rate × time

d = (90 km/hr) × (2 hr)

d = 180 km

2) Convert km/hr to m/s.

1 km = 1000 m, and 1 hr = 3600 s.

90 km/hr × (1000 m / 1 km) × (1 hr / 3600 s) = 25 m/s

So the truck moves 25 meters per second.

3) Distance = rate × time

10 km = (90 km/hr) × t

t = 1/9 hr

t = 6 min 40 sec

3. dark matter

empty space could also be a simple vacuum