Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Name________________________ Inclined Plane WS I. A block sits on an inclined plane whose surface makes an angle with the horizontal. The weight w of the block points straight down. Complete the table. Circle one: w (N) 50 30 50 45 50 60 w|| = w sin date__/__ w w = w cos a/ Since can be any angle, w can be resolved into (only 2/an ∞ number of) components. b/ If the incline is tilted up more, the angle (decreases/increases/remains the same). c/ As increases, the ||-component of the weight (decreases/increases/remains the same). d/ As increases, the -component of the weight (decreases/increases/remains the same). e/ As increases, the weight (decreases/increases/remains the same). II. No Friction. If the incline is fricitionless, the only force causing motion along the surface is w|| = wsinmgsinNewton’s Second Law then says: FN a = Fnet/ m = What will be the acceleration if the angle = 300? w|| If equals 600? w If it is 900? w 0 If it is 0 ? Do the answers depend on the mass? III. At Rest. If the block is at rest, the forces acting on the block are in equilibrium, so Fnet = ______ . In the diagram at right, a 50-N block is at rest on an incline that makes an angle of 300 to the horizontal. The weight has been resolved into w|| and w . Draw in the normal force, FN, and the frictional force, Ff. Using w|| = from the table above, what is Ff? Using w = from the table, what is FN? If were increased to 450 and block remained at rest, what would be the new value of Ff? What would the new value of FN be? w|| 300 w Q1. A 30.0-N block is at rest on an inclined plane whose surface makes a 240 angle to the horizontal. a/ Find the components of the weight that are parallel (w||) and perpendicular(w ) to the surface. w|| = w = b/ What are the magnitudes of the force of friction and the normal force? Ff = FN = c/ If the angle were increased, what would happen… …to Ff? …and to FN? Q2. A 10.0-kg crate is at rest on an inclined plane whose surface makes a 470 angle to the horizontal. a/ Find w|| and w . Be careful! Is it the mass or the weight of the crate that is given? w|| = w = b/ What are the magnitudes of the force of friction and the normal force? Ff = FN = c/ If the angle were decreased, what would happen… …to Ff? Q3. …and to FN? Circle the correct answers: As the angle of an inclined plane increases,…. …the frictional force acting on a block at rest on the incline (decreases/increases/remains the same). …the normal force acting on a block at rest on the incline (decreases/increases/remains the same). …the weight on a block at rest on the incline (decreases/increases/remains the same). Q4. A 15-N block is held at rest on a frictionless incline by a string as shown at right. string a/ Find the tension in the string. b/ How would the tension change if the incline angle were increased? 320 Q5. A 20.0-N block is at rest on a frictionless inclined plane. The block is held in place by a string hung over the pulley and attached to a weight. string pulley block pulley weight 350 a/ What is the tension in the string? b/ How much does the weight weigh? (Hint: the pulley just changes the direction of the tension.) c/ If the angle were increased, what would have to be done in order to keep the block at rest?