What Experiments Demonstrate Force Vs Power Differences?

I still get a kick out of simple physics demos that friends can replicate at home. Quick list of experiments that clearly separate force from power: (1) Lift a weight slowly vs quickly (same force to hold it, very different power — compute mgh/t). (2) Use a spring scale pulling a cart at two speeds; force might be steady but power = F·v grows with speed. (3) Drop a small mass on a force sensor and then slowly lower it — big force spike and short time versus small force over long time shows how power can be huge during impacts. (4) Pedal a bike at the same resistive torque but change cadence; measure watts with a power meter to see torque × angular velocity = power.

If you want measurements without lab gear, use a stopwatch, tape measure, a kitchen scale (for approximate masses), and a smartphone app like 'phyphox' to log acceleration or timing. Be mindful of safety for impact tests, and watch out for timing errors with hand stopwatches — repeat trials and average them. Try comparing results with a friend: one holds the weight steady while the other times lifts at different speeds, and you’ll all argue over who’s the most powerful in the group while learning actual physics.

My curiosity always lights up when a simple tabletop experiment makes a deep physics idea obvious — like how force and power are completely different beasts even though people use them sort of interchangeably in casual talk. Force is a push or pull (Newtons). Power is how fast you do work (Watts = Joules/second). One of my favorite demonstrations is embarrassingly low-tech: pick a 2–5 kg dumbbell, mark 1 m on a wall or use a meter stick, and time how long it takes to lift it vertically that distance. Calculate the work as mgh and divide by your time to get average power. Do the lift slowly and then do it quickly (but safely): you’ll feel the same force needed to support the weight, yet the power numbers will be very different. It’s a neat way to show friends that stronger doesn’t always mean more powerful — speed matters.

If you want something a bit more lab-like, pair a force sensor (or a spring scale) with a velocity measurement — a photogate, a smartphone gyroscope, or the 'phyphox' app on a phone. Attach a bungie or spring to a cart, pull with a roughly constant force and release; log force and speed vs time. Instantaneous mechanical power is P = F · v, so when the velocity is high the power spikes even if the force is unchanged. Another version: use a pulley and raise a mass at two different steady speeds. The force on the rope (ignoring friction) is basically the weight, but work/time changes with the lifting speed, so recorded power tracks speed directly.

For dramatic contrast, try a drop-impact test vs a slow lowering: drop a small mass onto a force sensor (use safety shielding) and compare the tall, narrow force spike to the gentle, longer low-force trace when you lower the same mass slowly onto a pad. The energy delivered can be similar, but because the drop delivers it in a much shorter time, the instantaneous power and peak force can be enormous. More advanced: measure torque on a bicycle crank while changing cadence; torque (force) might stay similar, but multiplying by angular velocity shows power climbing at higher cadences. I’ve done a couple of these with friends on a bike trainer and it completely changed how we trained — sprint power vs strength needs different drills. If you try any, note measurement errors (friction, reaction time with stopwatches) and basic safety, and you’ll walk away with a much clearer, hands-on sense of why force and power are distinct and how they both shape real motion and machines.