Two workers are moving a slab of ice (m = 410 kg) across the factory floor. As seen from above, one worker exerts a force of 255 N at an angle of -50o, and the other exerts a force of 375 N at an angle of 45o. What is the magnitude of the acceleration of the ice slab? At what angle does the ice slab accelerate? Your answer should be between -180o and +180o.