Aquarterback throws the football to a stationary receiver who is 16.1 m down the field. the football is thrown at an initial angle of 38.1 ◦ to the ground. the acceleration of gravity is 9.81 m/s 2 . a. at what initial speed must the quarterback throw the ball for it to reach the receiver? answer in units of m/s.

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.