PY 205 Ch2 HW7

1. [-/3 Points] DETAILS MY NOTES A soccer ball is kicked at an angle of 580 to the horizontal with an initial speed of 17 m/s. Assume for the moment that we can neglect air resistance. (a) For how much time is the ball in the air? (b) How far does it go (horizontal distance along the field)? (c) How high does it go? m Additional Materials weBook Submit Answer 2. [-/2 Points] DETAILS MY NOTES A 97 gram apple falls from a branch that is 2 meters above the ground. (a) How much time elapses before the apple hits the ground? (b) Just before the impact, what is the speed of the apple? m/s Additional Materials WeBook 3. [-/1 Points] DETAILS MY NOTES A rock is launched vertically upward by a slingshot. The elastic band of the slingshot accelerates the rock from rest to 40 m/s in a distance of 10 cm. How long will the rock take to return to its release point (time of flight)? Neglect air resistance. 3.1s 0 8.2 s 0 4.1s 1.2 5 0 16 s 4. [-/1 Points] DETAILS MY NOTES A particle moving parallel to the x axis is at x = 2 m at t = 0 and its velocity as a function of time t is given by v = 4t + 9t- where v is in m/s when t is in seconds. What is the equation giving the particle's displacement x as a function of time? O x - 2+ 412 - 2+3 Ox = 2 + 212 + 3+3 x = 4 + 18t Ox = 2 + 212 - 6+3 x = 4 - 18t5. [-/1 Points] DETAILS MY NOTES The position of a particle moving along the x axis is given by x = (21 + 22t - 6-) m, where & is in seconds (s). What is the instantaneous velocity at t = 2 s? 0 -24 m/s 0 22 m/'s 10 m/s o -2.0 m/s 0 46 m/'s 6. [-/1 Points] DETAILS MY NOTES A ball is thrown in a horizontal direction from the roof of a building with an initial speed of 20 m/s. The ball strikes the ground 120 m from the base of the building as shown. How high is the building? Q-. + 20 9 F=- 120m - 0 64 m 0 240 m 0 176 m 29 m 0 353 m 7. [-/1 Points] DETAILS MY NOTES A projectile is launched at 37 degrees to the horizontal with a speed of 200 m/s from position A. How many seconds elapse after launch of the projectile before it returns to its original elevation at C? 200 m/5 O 24 5 0 33 5 12 s 0 41 s 0 16 5