Two blocks (1st 1 from left to right 25kg, 2nd one 5kg) are connected by a cord on a horizontal. A force of 120N pulls on the blocks towards the right. Find the acceleration of the blocks and the tension in the connecting cord if (a) the surface is frictionless, and (b) the coefficient of kinetic friction is 0.20
2007-07-29 20:36:58 · 3 answers · asked by Mafia Agent 4207 5 in Science & Mathematics ➔ Physics
Two block together weigh at 30 kg.
For part a:
Acceleration: F = ma
120 = 30a
a = 4m/s
Connection: F = ma
F= 25x4
F = 100N
For part b:
Acceleration: Fres = ma
Fres = F - mCfr
Fres = 120 - 0.2x30x9.81
Fres = 61.14 or 60 if you use g = 10
61.14 = 30a
a = 2.038 or 2 if you use g = 10
Connection: F = ma
F = 25x2.018
F = 50.98 or 50 if you use g = 10
2007-07-29 21:10:07 · answer #1 · answered by Xenoblitz 2 · 0⤊ 0⤋
m1=25kg,m2=5kg. case 1: 120N -- T = 25 x a ; case 2: T =5 x a => 120 --5a=25a =>a = 4 = acceln., T=tension=20 N...frictionless surface.
2007-07-30 04:07:32 · answer #2 · answered by Mo 2 · 0⤊ 0⤋
(a) w/o friction,
a = 120/30 = 4 m/s^2
T = 25*4 = 100N
(b) μ = 0.2
a = (120 - 0.2*30*9.80665)/30 = 2.0267 m/s^2
T = 25(2.0267 + 0.2*9.80665) = 99.70075 N
2007-07-30 04:13:16 · answer #3 · answered by Helmut 7 · 0⤊ 0⤋