Some dogs – especially smaller breeds – pull with a force more than twice their body weight on the collar, potentially damaging their throats, says Erin Perry at Southern Illinois University.

A push or a pull is a force. Forces can make things move, change their speed, or change their shape. We cannot see a force but we can see its effects. Look at this toy car. It isn’t going anywhere.

Pull-ups are one of the most coveted bodyweight exercises for strengthening your upper body, namely your back, biceps and posterior deltoids (the rear shoulder muscles). For many, it’s a long ...

So there's no real force flinging you outwards, it's just that because you're moving, your body wants to go in a ... must be an inward-- a force inwards pulling it in, and that's called ...