When launching a spacecraft from the Earth, a propulsion method must overcome a higher gravitational pull to provide a positive net acceleration.

When measured as a function of mean solar time rather than uniform time, the effect appears as a positive acceleration.

Our acceleration's still positive!

The same is true for the minimum, with a vehicle that at first has a very negative velocity but positive acceleration.

Thus the negative of a negative gradient yields positive acceleration toward a massive object.

Today, most cams have mirror image (symmetric) profiles with identical positive and negative acceleration while opening and closing valves.

An exception is during positive acceleration when the engine power is driving two or fewer wheels.

When the driver presses on the brake or gas pedal, the accelerometer will register positive or negative acceleration.

Mr President, a positive acceleration is taking place in European political integration.

"No matter which one you pick out we'll have to have quite a lot of positive acceleration yet before we reverse to negative."