- What happens when you throw a ball horizontally?
- How does gravity affect a ball that is thrown horizontally?
- What direction is the net force on a falling skydiver before she reaches terminal velocity?
- What happens to the motion of ball if you throw the ball at an angle to the vertical?
- Will a thrown ball or a dropped ball hit the ground first when dropped or thrown from the same height?
- Does it take longer for a ball to go up or down?
- Does a ball go faster up or down?
- Is positive acceleration always speeding up?
- Can an object have zero velocity and non zero acceleration?

## What happens when you throw a ball horizontally?

The time required for initially horizontal projectile motion to occur is the same as the time required for the object to fall to its final height. Thus, a ball thrown horizontally will reach the ground at the same time as a ball dropped from the same height.

## How does gravity affect a ball that is thrown horizontally?

– An object thrown horizontally is accelerated downward under the influence of gravity. – The object’s horizontal velocity is unchanged, if we can neglect air resistance.

## What direction is the net force on a falling skydiver before she reaches terminal velocity?

upward

## What happens to the motion of ball if you throw the ball at an angle to the vertical?

If we stand at the edge of the roof of the Science Building and throw a ball up at an angle, it moves up and then down vertically while it moves horizontally. This is projectile motion.

## Will a thrown ball or a dropped ball hit the ground first when dropped or thrown from the same height?

In other words, if two objects are the same size but one is heavier, the heavier one has greater density than the lighter object. Therefore, when both objects are dropped from the same height and at the same time, the heavier object should hit the ground before the lighter one.

## Does it take longer for a ball to go up or down?

The answer is: Down. Only if there was no air resistance would the up and down times be the same.

## Does a ball go faster up or down?

This variance was due to the inclusion of air resistance in our model. Whilst on the way down, there is one force in the upward direction which increases as the ball gets faster (air resistance) and one constant force in the downward direction (gravity).

## Is positive acceleration always speeding up?

People think, “If the acceleration is negative, then the object is slowing down, and if the acceleration is positive, then the object is speeding up, right?” Wrong. An object with negative acceleration could be speeding up, and an object with positive acceleration could be slowing down.

## Can an object have zero velocity and non zero acceleration?

Yes. Anytime the velocity is constant, the acceleration is zero. For example, a car traveling at a constant 90 km/h in a straight line has nonzero velocity and zero acceleration. Its acceleration will change in magnitude and direction as the elevator starts and stops.