Mass will remain constant on both planet, let mass of the object be "m".
let x be the acceleration due to gravity on the surface of mars.
Weight of object on earth = m *g , where g is acceleration due to gravity on the surface of earth
⇒350 = m * 9.8
⇒m = 350 / 9.8 .............................equation(1)
Weight of object on mars = m * x , where x is acceleration due to gravity on the surface of mars
134 = m * x .............................equation(2)
putting the value of m from equation (1) in equation(2) , we get,
x = (134 * 9.8) / 350
⇒ x = 3.572 m/s²
