Question

why is it advisable to tie luggage

Answer 1

in a moving bus it is usually advisable to tie the luggage because when the car or bus would start or stop suddenly, the luggage may also move with a sudden force. this is because the luggage possesses inertia, i.e., the object tend to remain in motion when the bus is in motion or the object tend to remain at rest when the bus is in rest.

Answer 2

It is advisable to tie luggage that is kept on the bus.

When a bus starts to move the luggage will fall due to inertia of rest and when the bus stops the luggage can also fall due to inertia of motion.
It may harm the passengers sitting below.

Hope This Helps!