4. What is the acceleration of a box weighing 665 N if a force of 777 N is applied to it? (Hint: solve for the box's mass first, then plug in to acceleration equation). 5. What is the net force needed to accelerate the grocery sack with a mass of 21.4 kg upward at 1.5 m/s? 6. If 2.2 lbs = 1.0 kg, and Ariana Grande weighs 120 lbs, what is her weight in newtons? 7. A tennis ball, 0.314 kg, is accelerated at a rate of 164 m/s when his by a professional tennis player. What force does the player's tennis racket exert on the ball?