Question

(1 point) An elastic bone is compressed 10 μm by a student's weight. The student picks up a very heavy backpack and the sam e bone compressed by an extra 5 um. (a) How many times heavier or lighter is the student than her backpack? mstudent 1.5 (b) How much more potential energy is stored in the compressed bone with the backpack on than without? withPack4 mbackpack (1 point) Two bananas have very similar shapes, but one is "twice as fat" as the other. How much heavier do you expect this banana to be? A. 1.5 times as heavy O B. 2 times as heavy O C. 4 times as heavy O D. 8 times as heavy E. 10 times as heavy (1 point) A car traveling at 80 km/h applies its brakes and comes to rest in 4.5 s (a) Convert 80 km/h to units of m/s 80 km/h- m/s (b) Assuming a constant acceleration, calculate its value acceleration m/s (c) How far did the car travel while the brakes were on? distance (1 point) (a) How high does a ball rise if thrown vertically upward at 7 m/s? h2.5 (b) How long does it take to reach its highest position? up0.7138 (c) How long does it take to return to your hand after leaving it? total0.2551 (d) What is its velocity when it strikes your hand?

Answer 1

let mass of student = m let mass of backpack=m Compression with student alone = a, = loum compression with student + backpack) = x 2 = 1045 =15 um let k be the spring constant Weight of student = mg=W, ga acceleration weight of backpack = mg = Wz due to gravity For stradents & mg = kx4, -- 0 For student & back back & imena. " (m+mTg = k 2 ---☺ ra by dividing @ by 0, we get rm. m+mg = kx2 mg - mum = 1+ = 15mm => M = 1.5-1 =) = 0.5 =) M=0.5m =) m = m = m = 2m =) Mstudent = 2 m back pack (6) Potential energy for m = U, = 3 Ka12 Potential energy for (m+ M) = U2 = KX22 =) U = ² x (100) and Up = K (15)2 =) U,= look and U2 = 225k 2 = 225K = 2.25 =) U₂ = 2.250, - Kai I loum .=) U with back = 2.25 Ujust student