Newton's first law is applicable

$Assertion$ : 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.

$A$ trolley of mass $300 \; kg$ carrying a sandbag of $25 \; kg$ is moving uniformly with a speed of $27 \; km/h$ on a frictionless track. After a while,sand starts leaking out of a hole on the floor of the trolley at the rate of $0.05 \; kg \cdot s^{-1}$. What is the speed (in $km/h$) of the trolley after the entire sandbag is empty?

An athlete does not come to rest immediately after crossing the winning line due to the

Newton's first law of motion describes the following:

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