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 ms -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/s 2
Chifunidwa: Chinthucho chidzakwera kufika pa (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 kasupe angagwire ndi...
A. 1,6 × 10-5 Joule
B. 6,4 × 10 -4 Joules
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
Funso: Mphamvu yomwe ingakhalepo ya masika
Yankho:
Gwiritsani ntchito deta yomwe ili pa graph kuti muwerengere nthawi yokhazikika ya masika.
Mphamvu yomwe ingakhalepo ya masika:
∆ EP = 1/2 kx 2
∆ EP = 1/2 (200 N/m) (0,08 m) 2
∆ EP = (100 N/m)(0,0064 m 2 )
∆ EP = 0,64 Nm
3. Pakati pa zinthu zotsatirazi:
(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 kumapeto kwake. F ikuyimira kulemera kwa katunduyo ndipo ∆L 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
Funso: 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 ∆L 2 = 1/2 (500 N/m)(0,1 m) 2 = (250 N/m)(0,01 m 2 ) = 2,5 Newton meters = 2,5 Joules.
Yankho lolondola ndi B.
5. Chithunzi (Fx) chikuwonetsa ubale pakati pa mphamvu ndi kutalika kwa kasupe. Kukula kwa mphamvu 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
Amadziwika kuti :
F = 40 Newton
Δ x = mamita 0,08
Funso : Mphamvu yomwe ingakhalepo ya masika?
Yankho :
Chokhazikika cha masika:
k = F / Δ x
Mphamvu yomwe ingakhalepo ya masika:
EP = ½ k Δ x 2 = ½ (F/ Δ x) Δ x 2 = ½ F Δ x
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
