3 mau nīnau e pili ana i ka hoʻohālikelike ikaika maʻamau
1. He 5 kg ke kaumaha o kahi poloka. Inā ʻo g = 10 m/s 2 , e hoʻoholo:
a) ke kaumaha o ka poloka
b) ka ikaika maʻamau inā kau ʻia ka poloka ma luna o kahi mokulele pālahalaha
c) ka ikaika maʻamau inā kau ka poloka ma luna o kahi mokulele i hoʻohālikelike ʻia e hana ana i kahi kihi o 30 o i ka pae ʻaoʻao
ʻIke ʻia:
ʻO ke kaumaha o ka poloka (m) = 5 kg
Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s 2
Makemake ʻia: w, N ma ka mokulele a me N ma ka piʻi
pāʻoihana:
a) Kaumaha o ke kaola
w = mg = 5 (10) = 50 Newton
b) ʻO ka ikaika maʻamau inā aia ka poloka i loko o kahi mokulele pālahalaha
N = w = 50 Newton
c) ʻO ka ikaika maʻamau inā aia ka poloka ma kahi mokulele inclined
N = w y = w cos θ = 50 (cos 30) = 50 (½ √3) = 25√3 Newtons
2. Ua paʻi ʻia kahi mea holoi he 120 gram i ka papa me ka ikaika o 15 N. He aha ka ikaika maʻamau e hana ana ma luna o ka mea holoi?
Kaulana:
Nuipaʻa (m) = 120 grams = 0.12 kg
Ikaika (F) = 15 Newton
Makemake ʻia: Ka ikaika maʻamau
pāʻoihana:
Ikaika maʻamau = paʻi = 15 Newtons
3. Huki ʻia ka wai inu ʻōmole i loko o ka pahu me ka ikaika o F = 200 N e hana ana i kahi kihi o 37 o me ka ʻaoʻao pae. Sin 37 o = 0.6. ʻO ke kaumaha o ka pepa pahu a me kona mau mea i loko he 20 kg. Inā ʻo ke koina o ka friction static ma ka papahele he 0.5 a ʻo ke koina o ka friction kinetic ma ka papahele he 0.2, e hoʻoholo i ka ikaika maʻamau e hana ana ma ka pepa pahu.
ʻIke ʻia:
Ka ikaika huki (F) = 200 N
Hewa 37 = 0,6
Fy = F hewa 37 = (200)(0,6) = 120 N
Ka nui o ka pepa pahu (m) = 20 kg
ʻO ke kaumaha o ka pepa pahu (w) = mg = (20)(10) = 200 N
Makemake ʻia: Ka ikaika maʻamau ma ka pepa pahu (N)
pāʻoihana:
E helu i ka ikaika maʻamau me ka hoʻohana ʻana i ke ʻano hana ikaika maʻamau:
N = w – F y = 200 – 120 = 80 Newtons
