A box weighing 1000N is dragged across a level floor at a constant speed under the influence of a 50N applied force. What is the coefficient of sliding friction between the box and the floor? Sketch a free body diagram [FBD] - you should include four forces for full credit. Do not forget to label Fnet on FBD [direction and/or value] A 40kg child wants to slide down the slide, which is inclined at an angle of 53 degrees above the horizontal. In an effort to make the ride more thrilling, the evil babysitter pulls on the child with a horizontal rope which exerts a 20N force as shown in the diagram. Draw a free body diagram and include the 4 forces, including friction, which are acting on the child. Be sure to include your choice of x and y axes as well. [Keep in mind that if you tilt your axes like we did in class for a cart down a ramp other forces end up at an angle right but it makes one axis kind of nice.] What is the magnitude of the normal force acting on the child? Do not forget your force table. Every force exerted by an object, is also paired with a force exerted back on that object. The forces are equal in magnitude, opposite in direction, act on different objects (this means they will never both show up on a single F.B.D.) and are the same type of force. This means that when the leash pulls (tension) on Sir Isaac, my dog, he is also pulling on the leash (tension). 1. Review the well-known 3 rd Law of Newton and then consider a head-on collision between two vehicles on an icy, frictionless road. This collision was done as part of a government safety test - the only passengers were crash test dummies. The first vehicle is a tiny 800 pound electric car. The second is the massive 6500 pound 26 foot long oversized sport utility vehicle, HMMWV/Hummer H200. a. Which vehicle experiences the greater force during the collision? [circle your answer] The electric vehicle The Hummer Neither - they are the same Can't Tell b. Which vehicle has the greater acceleration during the impact? [circle your answer] The electric vehicle The Hummer Neither - they are the same Can't Tell c. Which vehicle has the greater change in velocity? [circle your answer] The electric vehicle The Hummer Neither - they are the same Can't Tell 2. Find the terminal velocity of a person falling in the air for a 120.0 kg sky diver. Assym that the cross section area of the air is 0.140 m2 Recall the density of air is p= 1.21 kg/m 3 and the coefficient of drag in air is C 0.70. 3. Lets say we have a mass hanging by a spring. The mass is 5 kg and is pulled back 10 cm. This experiences a net Force of 1000 N. What is the spring constant, k, of this spring? [Don't forget to show units here.]