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Name: _______________________ Free-Fall and Newton’s 2nd Law Block #: ______ Date: _________ The following picture is a skydiver. Assuming no air-resistance, calculate the following velocities and distances fallen. Use the equations vf = vi + gt and d = ½ gt2 (use acceleration because of gravity on the Earth as 9.8 m/s2). Show all work in the space provided. t=0s 0 m/s 0m vf = __________ d = _________ Direction of down acceleration: __________ t=1s vf = __________ d = _________ Direction of acceleration: __________ t=2s vf = __________ d = _________ Direction of acceleration: __________ t=3s vf = __________ d = _________ Direction of acceleration: __________ Find the acceleration of the boxes below using Newton’s 2nd law of motion: 1.) 10 kg Direction: _____________ 9N 2N 2.) a = _____________ 2N a = _____________ 10 kg Direction: _____________ 9N Answer the questions using the picture to the right Draw and label all four forces acting on the box: 1.) If the pulling force is 150 N and the box doesn’t move, what is the magnitude of friction? _______ 2.) If the force of sliding friction is 250 N, what force is necessary to keep the crate sliding at a constant velocity? _______________ The following is a picture of tandem skydivers where gravity and air-resistance are both forces acting on them. The first skydiver has a mass of 98 kg and the second skydiver has a mass of 102 kg. Calculate the net force and acceleration for each picture. A Fnet = _________ a = _____________ Direction of acceleration = __________ Fw = _______ 500 N Fr = _______ Fnet = _________ B a = _____________ Direction of acceleration = __________ Fw = _______ 1960 N Fr = _______ Fnet = _________ a = _____________ C Direction of acceleration = __________ Fw = _______ 2100 N Fr = _______ Fnet = _________ D a = _____________ Direction of acceleration = __________ Fw = _______ 1.) At which position (A, B, C, or D) are the skydivers going the slowest? ______________ 2.) At which position (A, B, C, or D) are the skydivers going the fastest? ____________ 3.) At which position (A, B, C, or D) are the skydivers falling at a constant velocity? ____________