1. You lift a 5.5kg box up off of the floor. The box goes from rest to a velocity of 2.4m/s upward as you lift it a distance of 1.Im. (a) Draw a free-body diagram for the box. (b) What is the acceleration of the box? (c) Using Newton's Second Law and your answer to part (a), what is the net force on the box? (d) What is the magnitude of the force you are exerting on the box to lift it? 2. Two children push a 17.0kg sled on ice. One child pushes with a force of -28.2Ni + 16.8Nj. The sled has an acceleration of -2.34m/s2i + 1.73m/$2j. (a) Using Newton's Second Law, what is the vector form of the net force on the sled? (b) What is the vector form of the force the second child exerts on the sled? 3. A 1400kg car collides with a truck traveling in the opposite direction. During the collision, the truck exerts a 3.6 x 10N force on the car. (a) What is the magnitude of the force exerted by the car on the truck? (b) If the truck's acceleration during collision has magnitude 450m/s2, what is the mass of the truck? (c) What is the magnitude of the car's acceleration? 4. A man pushes a 22kg grocery cart on a flat, level floor with a force of 180N. He pushes at an angle of 20 below the horizontal. Assume that there is no friction. (a) Draw a free-body diagram for the cart. (b) What is the acceleration of the cart? (c) What is the magnitude of the normal force on the cart?45 30 A P C M 5. A block of mass M = 11.0kg hangs from the ceiling by a system of ropes as shown above. (a) Draw a free-body diagram for the block. (b) What is the magnitude of the tension in rope C? (c) Since the knot connecting ropes A, B and C is not moving, the net force on it must be zero. Draw a free-body diagram for the knot. You may assume that the rope (and, therefore, the knot) is massless. (d) Write an expression for the net force on the knot in the vertical direction. Your expression may contain the tension in each rope TA, TB and To, and trigonometric functions sin and cos. Not all of these quantities will appear. (e) Write an expression for the net force on the knot in the horizontal direction. Your expression may contain the tension in each rope TA, TB and To, and trigonometric functions sin and cos. Not all of these quantities will appear. (f) What is the magnitude of the tension in rope A? (g) What is the magnitude of the tension in rope B? 6. A 0.50kg mass hangs from a spring. a) If the spring is stretched 8.6cm from its equilibrium position due to the weight, what is the spring constant? (b) How far would the same mass stretch a spring with k = 120N/m? N