#7 Two ropes pull a mass across a rough floor as shown below. The ropes have ide
ID: 1266028 • Letter: #
Question
#7 Two ropes pull a mass across a rough floor as shown below. The ropes have identical tensions T1=T2=25 N. Friction opposes the motion with a force of f=18 N. A) What is the net force acting on the mass? Three charged objects A, B and C are arranged as shown below. All three objects have the same magnitude of charge, 15 nC, but objects A and C are negatively charged while object B is positively charged. All the dashed line distances shown are the same, 5.0 cm. B) What is the Electric Field strength at the point marked with an, ?X?? C) If I put an object with charge + 5.0 nC at the point marked ?X?, what force would act on it? D) What is the same between part ?A? and part ?B??Explanation / Answer
7)
A) Fnet = sqrt(T1^2 + T2^2 + 2*T1*T2*cos(60))
= sqrt(25^2 + 25^2 + 2*25*25*cos(60))
= 43.3 N <<<<------Answer
B) distance from B to x, d = 2*5*sin(60)
= 8.14 cm
= 0.0814 m
EA = EC = k*q/L^2
= 9*10^9*15*10^-9/0.05^2
= 54000 N/c
EAC = sqrt(EA^2 + EB^2 + 2*EA*EB*cos(60))
here, EA = EB
so, EAC = sqrt(3)*EA
= sqrt(3)*5400
= 93530 N/c (upward)
EB = k*q/d^2
= 9*10^9*15*10^-9/0.0814^2
= 20374 N/c (downward)
Enet = EAC - EB
= 93530 - 20374
= 73156 N/c (upward) <<<<------Answer
c) F = q*E
= 5*10^-9*73156
= 3.66*10^-4 N <<<<------Answer
D) Net force is upward <<<<------Answer
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.