David rides his bike with a constant speed of 12 miles per hour. How long will it take to travel a distance of 18 miles?

1.50 h

Explanation:

For an object moving in uniform motion (= moving at  cosntant velocity), the relationship between speed, distance and time is given by:

where:

v is the speed of the object

d is the distance covered

t is the time taken to cover the distance

For this problem, we have:

d = 18 miles is the distance covered by David

is David's speed

Therefore by re-arranging the equation, we can find the time taken by David to cover that distance:

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6

probably not if net force is zero