If anyone could help me with these problems, I'd be eternally grateful ... 1) The distance between two telephone poles is 51.0 m. When a 0.800 kg bird lands on the telephone wire midway between the poles, the wire sags 0.210 m. How much tension does the bird produce in the wire? Ignore the weight of the wire. 2) A block slides down a friction-less incline having an angle of 17.0 degrees. Assume that the block starts from rest at the top and the length of the incline is 2.60 m. Take the direction of motion as the positive direction. What's the acceleration of the block? 3) A 21.0 kg block is initially at rest on a horizontal surface. A horizontal force of 78.0 N is required to set the block in motion. After it is in motion, a horizontal force of 59.0 N is required to keep the block moving with constant speed. Find the coefficients of static and kinetic friction from this information. 4) A woman at an airport is towing her 20.0 kg suitcase at constant speed by pulling on a strap at an angle of (theta) above the horizontal. She pulls on the strap with a 35.0 N force, and the friction force on the suitcase is 20.0 N. What angle does the strap make with the horizontal? What normal force does the ground exert on the suitcase?