Question

Truck drivers approaching a steep hill that they must climb often increase their speed. What good does this do, if any?

Answer 1

The faster you are going when you hit the hill the longer it will take gravity to slow you down. It just makes it easier to get up the hill when you have a huge load. If you think about acceleration on a slant gsinΘ even if there wasn't friction they would slow down at a constant rate.