This is a mechanical engineering problem.
The motor specification sheet provides:
The rated output power. That is the mechanical power that the motor can deliver to drive the load continuously.
The rated speed. That is the motor speed at which it can deliver the rated output power.
The rated torque. That is the torque that the motor will be providing when operating at rated speed and power. The motor can probably provide the same torque down to zero speed when controlled by a well designed speed controller. The maximum time of operation will be determined by the motor cooling system.
Mechanical output power in watts is equal to the speed in RPM multiplied by the torque in newton-meters divided by 9.549.
The maximum speed of the vehicle will be determined by the driving wheel diameter and the speed ratio between the motor shaft and the wheel. The speed may also be limited by the torque available to overcome the load.
The load presented to the motor by the vehicle consists of rolling friction, drive train friction, aerodynamic drag, force required to accelerate inertia at the desired rate and force required to raise mass up an incline.
Friction is a constant retarding force or torque that doesn't change much with speed. It is the coefficient of friction multiplied by weight or force.
Aerodynamic drag is the retarding force of the vehicle moving through air. It is proportional to speed squared multiplied by a drag coefficient.
The force required for acceleration is mass multiplied by the rate of acceleration.
The force required to raise mass up an incline (climb a hill) is determined by the force of gravity acting on the mass and the angle of incline.
There are handbooks and online sources that may be able to provide coefficients of friction for various types of driving wheels, bearings, chain drives etc. Drag coefficients may also be available.
The basics of applied mechanics - statics and dynamics can be found in text books, course notes and online tutorials.
Working out the details is a problem that is too broad for this forum. It is also off-topic for the electrical engineering section except that is is useful for an electrical engineer to understand the basics and the general principals as outlined above.