$A$ reference frame attached to the Earth cannot be an inertial frame because

An astronaut accidentally gets separated from his small spaceship accelerating in interstellar space at a constant rate of $100 \; m/s^2$. What is the acceleration of the astronaut the instant after he is outside the spaceship (in $; m/s^2$)? (Assume that there are no nearby stars to exert gravitational force on him.)

Which of the following persons is in an inertial frame of reference?

$Assertion$ : The driver in a vehicle moving with a constant speed on a straight road is an inertial frame of reference.
$Reason$ : $A$ reference frame in which Newton's laws of motion are applicable is non-inertial.

Inertia is that property of a body by virtue of which the body is

$A$ man getting down from a running bus falls forward because: