Zitsanzo 5 za Mafunso Okhudzana ndi Mphamvu
Mphamvu Yokoka
1. Mphamvu zokwana ma Joules 4.900 zimagwiritsidwa ntchito kunyamula chinthu cholemera makilogalamu 50 molunjika. Chinthucho chidzakwera kufika kutalika kwa … (g = 9,8 m/s).-2 )
A. 0,1 m
B. 10 m
C. 98 m
D. 245 m
E. 960 m
Zokambirana
Amadziwika kuti:
Kusintha kwa mphamvu zomwe zingatheke (ΔEP) = 4900 Joules
kulemera kwa chinthu (m) = 50 kg
Kuthamanga chifukwa cha mphamvu yokoka (g) = 9,8 m/s2
Anafunsa kuti: Chinthucho chidzakwera kufika kutalika (Δh)
Yankho:
ΔEP = mg Δh
4900 = (50)(9,8) Δh
Δh = mamita 10
Yankho lolondola ndi B.
Mphamvu Yotheka ya Masika
2. Chithunzi chotsatirachi chikuwonetsa ubale pakati pa F (mphamvu) ndi x (kuwonjezeka kwa kutalika) kwa kasupe. Ngati kasupe wasokonekera ndi 8 cm, ndiye kuti mphamvu yomwe ingakhalepo ya kasupe ndi...
A. 1,6 × 10-5 Joule
B. 6,4 × 10-4 Joule
C. 8 Joule
D. 16 Joule
E. 128 Joule
Zokambirana
Amadziwika kuti:
Mphamvu (F) = 2 Newtons
Kuwonjezeka kwa kutalika (x) = 1 cm = 1/100 mita = 0,01 mita
Kupatuka kwa masika = 8 cm = 8/100 mamita = 0,08 mamita
Anafunsa kuti: Mphamvu yothekera ya masika
Yankho:
Gwiritsani ntchito deta yomwe ili pa graph kuti muwerengere nthawi yokhazikika ya masika.
Mphamvu yomwe ingakhalepo ya masika:
∆EP = 1/2 kx2
∆EP = 1/2 (200 N/m)(0,08 m)2
∆EP = (100 N/m)(0,0064 m2)
∆EP = 0,64 Nm
3. Zina mwa zinthu izi:
(1) Rabala yotambasulidwa ya slingshot
(2) Pendulum yopotoka
(3) Chitsulo chotentha
Zinthu zomwe zili ndi mphamvu zimawerengedwa...
A. (1)
B. (1) ndi (2)
C. (2)
D. (2) ndi (3)
E. (3)
Zokambirana
(1) Rabala yotambasulidwa ya slingshot
Rabala ya slingshot ikatambasulidwa imakhala ndi mphamvu yotha kusinthasintha.
(2) Pendulum yopotoka
Pamene pendulum yatembenuzidwa, pendulum imakhala ndi mphamvu yokoka.
Yankho lolondola ndi B.
4. Gome ili m'munsimu likuwonetsa zotsatira za kuyesera kokhudza kasupe wokhala ndi katundu wogwiritsidwa ntchito kumapeto amodzi. F ikuyimira kulemera kwa katunduyo ndipo ΔL ikuyimira kuwonjezeka kwa kutalika. Werengani ntchito yofunikira kuti kasupeyo awonjezere ndi 10 cm.
A. 2,0 Joule
B. 2,5 Joule
C. 5,0 Joule
D. 7,6 Joule
E. 10 majoule
Zokambirana
Amadziwika kuti:
Kuwonjezeka kwa kutalika kwa masika (∆L) = 10 cm = 0,1 mamita
Anafunsa kuti: Kuyesetsa kukulitsa kasupe ndi 10 cm
Yankho:
Gwiritsani ntchito deta yomwe ili patebulo kuti muwerengere nthawi yokhazikika ya masika:
k = F / ∆x = 20 N / 0,04 m = 500 N/m
k = F / ∆x = 30 N / 0,06 m = 500 N/m
k = F / ∆x = 40 N / 0,08 m = 500 N/m
Mphamvu ya kasupe ndi 500 N/m
Kuyesetsa kukulitsa kasupe ndi 10 cm ndi:
W = 1/2 k ∆L2 = 1/2 (500 N/m)(0,1 m)2 = (250 N/m)(0,01 m2) = 2,5 Newton meters = 2,5 Joules.
Yankho lolondola ndi B.
5. Chithunzi (Fx) chikuwonetsa ubale pakati pa mphamvu ndi kutalika kwa kasupe. Mphamvu yomwe ingakhalepo ya kasupe kutengera chithunzi pamwambapa ndi…
A. majoule 20
B. 16 majoule
C. 3,2 majoule
D. 1,6 majoule
E. 1,2 majoule
Zokambirana
Ndizodziwika kuti :
F = 40 Newton
Δx = mamita 0,08
Anafunsa Mphamvu zomwe zingatheke pa kasupe?
Yankhani :
Chokhazikika cha masika:
k = F / Δx
Mphamvu yomwe ingakhalepo ya masika:
EP = ½ k Δx2 = ½ (F/Δx) Δx2 = ½ F Δx
EP = ½ (40)(0,08) = (20)(0,08) = 1,6 Joules
Yankho lolondola ndi D.
Gwero la funso:
Mafunso a National Examination Physics a Senior High School/Vocational High School
