According to Dr. The iPhone 15 Pro will likely feel significantly lighter than the iPhone 14 Pro, not only because of the switch from stainless steel to titanium, but also because of the change in the device’s moment of inertia. LeanCrew Blog.
The iPhone 15 Pro weighs 187 grams, 9% less than the iPhone 14 Pro’s 206 grams. In its announcement, Apple emphasized that the new lightweight design was facilitated by switching from a stainless steel to a titanium frame. Including those who have already spent some time with the “iPhone 15 Pro”. MacRumorsDan Barbera noted how light the device is in the hand. However, new analysis shows that the iPhone 15 Pro will appear lighter than its actual weight due to changes in moment of inertia.
Moment of inertia, a fundamental concept in physics, measures a body’s resistance to rotational motion. Its value is determined by how much mass the object has and how that mass is distributed. More importantly, the further the mass is from the body’s axis of rotation, the greater the moment of inertia. For frequently handled objects like smartphones, rolling resistance plays an important role in how heavy or light they feel in everyday use.
Apple’s switch from stainless steel to titanium for the iPhone 15 Pro’s outer band is crucial to this change, as much of the phone’s weight reduction is on the outer edge. Analyzing Dr. Drang shows that by reducing mass, especially at the periphery, Apple has achieved a reduction in the phone’s moment of inertia that is more significant than expected based solely on the massive weight loss.
This reduction, which represents more than an overall reduction, will make the iPhone 15 Pro easier to use and may reinforce the perception that it is much lighter than the 14 Pro.
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The reduction in circumferential mass that accompanied the switch from stainless steel to titanium must have reduced the moment of inertia if the mass had been reduced equally. This makes the 15 Pro easier to handle and at least partially contributes to the impression of lightness.
Based on the analysis of the dimensions of the new phone and assuming that the overall reduction occurs primarily at the perimeter of the phone, the moment of inertia of the iPhone 15 Pro is expected to decrease by 14-15%. Overall, this means that the “iPhone 15 Pro” is not only lighter; Its design ensures that its mass is distributed so that it resists rolling movement with less force. This makes the device look more flexible and movable and gives an increased impression of lightness.
