Yes, it is true. According to Einstein’s theory of relativity, as an object with mass accelerates towards the speed of light, its relativistic mass increases. This means that the object becomes heavier in a sense as its speed approaches the speed of light.
When we talk about mass in this context, we’re often referring to the concept of relativistic mass, which can be thought of as the energy of the object divided by the speed of light squared. As an object’s speed increases, especially as it gets close to the speed of light, the energy required to continue accelerating it becomes larger and larger. In fact, to reach the speed of light, you would need an infinite amount of energy, which is impossible in our universe. Therefore, it’s not that the mass becomes infinite in a practical sense, but rather that the object cannot reach the speed of light at all, as doing so would require infinite energy.