Kev sib npaug ntawm cov cev ntawm lub dav hlau inclined - kev siv Newton txoj cai thawj zaug cov teeb meem thiab kev daws teeb meem

1. Ib lub thaiv 2-kg nyob rau ntawm ib lub dav hlau uas nkhaus ntawm lub kaum sab xis 37^o mus rau kab rov tav. Txheeb xyuas qhov loj ntawm lub zog sab nraud uas siv rau ntawm lub thaiv, yog li lub thaiv tsis txav mus rau hauv lub dav hlau. (syn 37^o = 0.6, cos37^o = 0.8, g = 10 ms^-2, µ_k = 0.2)

Paub:

Pawg (m) = 2 kg

Acceleration vim lub ntiajteb txawj nqus (g) = 10 m/s²

Cov Blocks hnyav (w) = mg = (2)(10) = 20 Newtons

Kev txhaum 37^o = 0.6

Kos 37^o = 0.8

Tus lej ntawm kev sib txhuam kinetic (µ_k= 0.2 TZS

Tus y-component ntawm qhov hnyav (w_y) = wb coj 37^o = (20)(0.8) = 16 Newtons

Tus x-feem ntawm qhov hnyav (w_x) = w sin θ = (20)(sin 37) = (20)(0.6) = 12 Newton

lub zog ib txwm (N) = w_y = 16 Newtons

xav Lub zog sab nraud (F)

tshuaj :

w_x = 12 Newtons

Lub zog ntawm kev sib txhuam kinetic (f)_k) = µ_k N = (0.1)(16) = 1.6 Newtons

Qhov loj ntawm lub zog sab nraud F uas siv rau ntawm lub thaiv :

F + f_k - w_x = 0

F = w_x - f_k

F = 12 – 1.6

F = 10.4 Newtons

Lub zog sab nraud F ntau dua 10.4 Newtons.

2. Qhov hnyav ntawm ib lub thaiv = 2 kg, coefficient ntawm kev sib txhuam static µ_s = 0.4 thiab θ = 45^oTxheeb xyuas qhov loj ntawm lub zog F kom lub thaiv pib txav mus rau saum.

Paub:

Tus coefficient ntawm kev sib txhuam static (µ)_s= 0.4 TZS

Lub kaum sab xis (θ) = 45^o

Kev nrawm vim lub ntiajteb txawj nqus (g) = 10 m/s²

Qhov hnyav ntawm lub thaiv (m) = 2 kilogram

Qhov hnyav ntawm lub thaiv (w) = mg = (2 kg) (10 m/s)²) = 20 kg m/s² = 20 Newtons

Tus x-feem ntawm qhov hnyav (w_x) = w sin θ = (20)(sin 45) = (20)(0.5√2) = 10√2 Newton

Tus y-component ntawm qhov hnyav (w_y) = w cos θ = (20)(cos 45) = (20)(0.5√2) = 10√2 Newton

xav Qhov loj ntawm lub zog F

Tshuaj:

Lub thaiv pib swb rau saum, yog tias F ≥ w_x + f_s.

Tus x-feem ntawm qhov hnyav:

w_x = 10√2 Newtons

y-feem ntawm qhov hnyav :

w_y = 10√2 Newtons

Lub zog ib txwm muaj :

N = w_y = 10√2 Newtons

Lub zog ntawm kev sib txhuam static :

f_s = µ_s N = (0,4)(10√2) = 4√2

Qhov loj ntawm lub zog F kom lub thaiv pib txav mus rau saum :

F ≥ w_x + f_s

F ≥ 10√2 + 42

F ≥ 14√2 Newtons

[wpdm_package id='492′]

1. Cov khoom me me hauv ib qho kev sib npaug
2. Cov khoom me me hauv qhov sib npaug ob sab
3. Kev sib npaug ntawm lub cev txuas nrog los ntawm cov hlua thiab pulleys
4. Kev sib npaug ntawm lub cev ntawm lub dav hlau inclined