Question

HOW DOES THE MASS OF AN OBJECT EFFECT THE SPEED THE OBJECT MOVES AT? and how would that impact the speed of a ball

Answer 1

Short answer: mass by itself does not always determine speed. What matters is how forces, energy, or momentum are applied. Different common situations give different relationships between mass and speed.

Key physics relations (useful to pick the right case)
- Newton’s 2nd law: F = m a => for a given force, acceleration a = F/m. So heavier objects accelerate less under the same force.
- Momentum: p = m v => for a given momentum, v = p/m, so heavier objects move slower for the same momentum.
- Kinetic energy: KE = 1/2 m v^2 => for a given kinetic energy, v = sqrt(2 KE / m), so heavier objects move slower if they have the same energy.

Common situations and what happens to a ball
- Same force applied (for the same time): A lighter ball gets a larger change of velocity. Example: if you push two balls with the same force for the same time, the lighter ball will end up faster.
- Same impulse (same push/ hit giving the same change in momentum): the lighter ball gets a bigger speed change because Δv = Δp / m.
- Same energy delivered (same KE): the heavier ball will be slower because v ∝ 1/√m. Example: if two balls both have 10 J of kinetic energy, a 0.2 kg ball has v = 10 m/s while a 0.8 kg ball has v = 5 m/s.
- Free fall in vacuum: mass does not affect acceleration due to gravity, so all masses fall the same and reach the same speed at the same time (ignoring air resistance).
- With air resistance: lighter or less dense balls are slowed more by drag; heavier balls usually reach a higher terminal velocity and therefore can be faster when falling or thrown through air.

Concrete numeric examples
- Same impulse J = 2 N·s: for m = 0.2 kg, Δv = J/m = 10 m/s. For m = 0.8 kg, Δv = 2.5 m/s.
- Same kinetic energy KE = 10 J: v = sqrt(2 KE / m). For m = 0.2 kg → v = 10 m/s. For m = 0.8 kg → v = 5 m/s.

Practical takeaway
- If you apply the same force (or the same hit) to two balls, the lighter one will generally end up moving faster.
- If you drop two solid balls in still air, the heavier one may reach the ground first because it is less affected by air resistance; in vacuum they fall equally fast.

If you want, tell me a specific scenario (throwing, dropping, hitting with a bat, same energy from a machine, etc.) and I’ll show the exact equation and a numeric example for that case.