Question

As the velocity of a body increases and becomes very close to the velocity of light the force needed to keep the body moving with a constant accerlation of 1m/s 2 is?

Answer 1

As the velocity of a body increases and becomes very close to the velocity of light we need infinitely large force to keep the body moving with a constant accerlation of $1\frac{m}{s^2}$.

Also we cannot keep this acceleration to get velocity greater than the velocity of light.