Worksheet: Force and Pressure
In this worksheet, we will practice defining pressure as the force per unit area and calculating pressures acting on a surface.
Why are sharper knives more effective at cutting?
- AThe smaller contact surface of a sharper knife can react faster with the surface of what is being cut.
- BThe sharper the knife, the greater the torque on the cutting surface.
- CSharper knives have smoother surfaces, allowing them to slide into the weak points of what is being cut.
- DSharper knives have smaller contact areas so, with the same force, this translates to a greater pressure.
Why should you roll or belly-crawl rather than walk across a thinly-frozen pond?
- AThe more of your body rests on the ice, the less you weigh.
- BActually, you should walk on tip-toe so that your body heat does not melt the ice.
- CIf you have more contact with the ice, the ice will warm up and expand, becoming more buoyant.
- DThe greater your contact area with the ice, the lower the pressure and the risk of it breaking.