Science Equipment for Measuring the Speed of Marbles
Stopwatch and Measuring Tape
- The first set of tools needed to measure the speed of any moving object is a stopwatch and measuring tape. The definition of a moving object's speed is the amount of time it takes for the object to cover a fixed distance. The most simple measurement of a moving marble's speed is obtained by tracking the time it takes for the marble to travel a known distance.
- A strobe light is another useful tool for determining the rate at which a marble travels and accelerates. For example, if a marble rolls off a level shelf and is allowed to fall under the influence of gravity, a strobe light can illuminate the marble's path at known time intervals. If the marble is photographed under these conditions, students will watch the marble accelerate and travel through a parabolic path as it accelerates towards the floor.
- Some motion experiments, such as the one described in Section 2, require students to photograph a moving marble to calculate its speed or acceleration. A simple Polaroid camera with a manually controlled shutter can create instant photographs to provide this information. More expensive digital cameras that have manual override controls on the shutter lens can take the same pictures in a digital format that can be manipulated on a computer screen.
Digital or Triple-Beam Scale
- Calculations that compute a force that propels a marble to a certain speed will need the weight of the marble as one of the variables. Accelerating a heavy marble to a specific speed requires more initial force than accelerating a light marble to the same speed. If students want to calculate the initial force that gets applied to a marble to obtain a specific speed, they need to measure the marble's mass on a digital or triple-beam balance scale.