Question

Show how a spring scale and a simple fulcrum can be used to weigh an object whose weight is larger than the maximum reading on the scale.

a) Increase scale sensitivity
b) Decrease scale sensitivity
c) Use a heavier fulcrum
d) Employ multiple scales

Answer 1

To weigh a heavy object with a spring scale exceeding its limit, use a simple fulcrum and levers; by placing the scale further from the fulcrum than the object to increase the scale's sensitivity. Calculate the actual weight using the distance ratio. No need for a heavier fulcrum or multiple scales.

Step-by-step explanation:

Using a Spring Scale and a Fulcrum to Weigh Heavy Objects

To weigh an object heavier than the maximum capacity of a spring scale, one can use a simple fulcrum and the principle of levers. The process involves setting the spring scale a certain distance away from the fulcrum and the heavy object at a different, ideally longer, distance from the fulcrum. The ratio of these distances will allow the smaller force measured by the scale to balance the larger weight of the object. This method effectively increases the scale's sensitivity. Here is how it works:

1. Place the fulcrum at a fixed point.
2. Attach one end of the object to be weighed to the fulcrum.
3. Position the spring scale at a known distance from the fulcrum on the opposite side of where the object is attached.
4. Measure the weight shown by the spring scale.
5. Calculate the actual weight of the object using the distances as a ratio.

For example, if the scale is placed 1 meter from the fulcrum, and the object is 4 meters from the fulcrum, the actual weight of the object is four times the measured weight on the scale. This setup multiplies the scale's effective range without needing a heavier fulcrum or employing multiple scales.

In contrast, to decrease scale sensitivity, reverse the process by placing the object closer to the fulcrum than the scale. This will require a larger actual weight to show the same reading on the scale, effectively making the scale less sensitive.

Regarding the Take-Home Experiment on mass and weight, a bathroom scale measures weight but is usually calibrated in mass units such as kilograms by dividing the weight in newtons by the acceleration due to gravity (9.80 m/s2). If one pushed down on a table while weighing on the scale, the reading would decrease because the force exerted on the scale lessens. And if the scale is taken to the Moon, it would not display the same mass because the gravitational pull is different; hence, the weight and the respective mass reading would be lower.