Question

Physics 031-Exam page 3 PART IL You must justify your answers in this part. For full credit, all questions in part II require simplified numerical answers in the blank spaces. II.1 A car is going around in a circle at constant speed v 10 units/s as shown in the figure. The squares are 1x1 units. (2x5 points) (a) Find the magnitude of the car's acceleration Answer (b) Find the x and y components of the car's acceleration. as" IL2 Two masses, m m and m2 2m are hanging from the ceiling of an elevator as shown in the figure. The elevator is accelerating down with acceleration a. (5 points) Find the ratio of the magnitudes of the tensions, TJTi lower rope upper rope) Answer

Answer 1

onl 22-34 unit/,- 4.47) 냐.YFㄴ 2. 3

m2g - T1 =m2.a ....... eqn1
T1 - T2 = m1.a ...... eqn2

from 1
T1 =m2 (g-a)

from 2
T2= m2(g-a)-m1.a =(m2 - m1)a-m2g

so T2/T1 = (m2 - m1)a-m2g/m2 (g-a)= ma-2mg/2m(g-a) = (a-2g)/2(g-a)