There is not enough information given to answer with. The force of gravity at the planet's surface depends on the planet's radius as well as its mass. The planet could have exactly the same mass as Earth has. But if it's radius is only 71% of Earth's radius, then gravity on its surface will be twice as strong as gravity on Earth.
Newton's first law of motion is an object in motion stays in motion until acted upon by another force. Driving at 30 mph in a car is going to stay constant until you crash the car into a wall, stopping the car.
