Acceleration of a space shuttle

when the space shuttle takes off, its acceleration gradually increases as it rises, explain why this happens in terms of Newtons second law?
i know it alot but it would be much appreciated, thank you :D

Newton's second law boils down to F=ma, where F is the force applied, m is the mass the force is being applied to, and a is the acceleration. Rearrange that and you get a = F/m.

The engines produce a (more or less) constant force when burning (in practice the main engines are throttled and the solid rocket boosters are designed so that their thrust varies over the duration of the burn, but for the purposes of this question they can be considered to be producing constant thrust). When they burn, they consume propellant and hurl it out the back. That means that as the engines burn the shuttle loses mass.

Since F is constant and a = F/m, as m gets smaller, so a gets bigger.

F=m*a

Force from the thrusters is roughly equal the entire launch,

Mass becomes smaller due to burning the fuel

Thus acceleration has to go up.