Piv txwv ntawm cov lus nug txog lub dav hlau inclined rau tsev kawm ntawv theem siab

4 Piv txwv ntawm cov lus nug txog SMP inclined plane

1. Saib daim duab hauv qab no!

Ib lub trolley uas hnyav 10 N raug rub tawm hauv qab ntawm lub dav hlau inclined kom txog thaum nws mus txog saum lub dav hlau inclined. Qhov loj ntawm lub zog F xav tau yog…

A. 15,0 N

B. 12,5 N

C. 5,0 N

D. 2,5 N

Kev Sib Tham

Nws paub tias:

Qhov hnyav ntawm lub laub (w) = 10 Newton

Qhov ntev ntawm lub dav hlau inclined = 2 meters

Qhov siab ntawm lub dav hlau inclined = 0,5 meters

θ = lub kaum sab xis ntawm lub dav hlau tiaj tus thiab lub dav hlau inclined

Sin θ = 0,5/2 = 0,25

Lus Nug: Qhov loj ntawm lub zog F

Lus teb:

w _x yog qhov sib xyaw ntawm qhov hnyav ntawm lub trolley uas sib luag rau lub dav hlau inclined

wy yog qhov sib xyaw ntawm qhov hnyav ntawm lub trolley uas yog perpendicular rau lub dav hlau _inclined

Yuav kom lub trolley raug rub mus rau saum, lub zog rub F yuav tsum tsawg kawg yog sib npaug rau w _x.

w _x = w sin θ = (10 Newton)(0,25) = 2,5 Newton

Yog li ntawd, lub zog tensile F = 2,5 Newton

Cov lus teb yog D.

2.

Ib yam khoom ua los ntawm ib lub thaiv ntoo du yuav raug tsa rau ntawm ib lub dav hlau du raws li pom hauv daim duab. Yog tias qhov hnyav ntawm lub thaiv yog 6 kg, g = 10 m/s², ces qhov loj ntawm lub zog thawb kom tsa lub thaiv ntawm P mus rau Q yog ...

A. 36 Newtons
B. 24 Newton
C. 20 Newton
D. 12 Newton

Kev Sib Tham

Berat nqaj: w = mg = (6)(10) = 60 kg m/s² = 60 Newtons
Cov blocks du thiab cov dav hlau inclined yog du yog li lawv suav tias tsis muaj kev sib txhuam. kev sib txhuamYuav kom lub thaiv txav mus rau sab saud, lub zog thawb tsawg kawg nkaus yuav tsum sib npaug rau qhov hnyav ntawm lub thaiv uas sib luag rau lub dav hlau inclined, uas yog w_x.
w_x = w sin teta = (w)(pem hauv ntej/hypotenuse)
w_x = (60)(20/60) = (60)(1/3) = 20 Newtons
Cov lus teb yog C.

3.

Ib tug neeg ua haujlwm xav tsiv lub thawv mus rau ntawm lub tsheb thauj khoom uas hnyav 500 Newtons siv lub dav hlau uas nkhaus raws li pom hauv daim duab hauv qab no. Yog tias lub tsheb thauj khoom siab 1,5 m, yuav tsum muaj zog npaum li cas los txav lub thawv?

A. 125 N
B. 250 N
C. 500 N
D. 1500 N

Kev Sib Tham
Qhov hnyav ntawm lub thawv (w) = 500 Newton
Yuav kom lub thawv txav mus rau sab saud, lub zog thawb tsawg kawg nkaus yuav tsum zoo ib yam li cov khoom ntawm lub thawv lub ntiajteb txawj nqus sib luag rau lub dav hlau inclined, uas yog w_x.
w_x = w sin teta = (w)(pem hauv ntej/hypotenuse)
w_x = (500)(1,5/3) = (500)(1/2) = 250 Newtons
Cov lus teb yog B.

4.
Ib daim khoom siv hnyav yuav tsum tau tsa siv lub plank ua lub dav hlau inclined, raws li qhia hauv daim duab hauv qab no. Yuav kom ntseeg tau tias lub zog tsa yog ib nrab ntawm qhov hnyav tiag tiag ntawm lub crate, lub plank nrog qhov ntev ntawm ...
A. 5,0 m
B. 7,5 m
C. 10,0 m
D. 12,5 m
Kev Sib Tham
Qhov hnyav ntawm lub thawv = w
Yuav kom lub thawv txav mus rau sab saud, lub zog thawb tsawg kawg nkaus yuav tsum sib npaug rau qhov sib xyaw ntawm lub thawv lub ntiajteb txawj nqus sib luag rau lub dav hlau inclined, uas yog w_xYog li ntawd qhov loj ntawm lub zog thawb yog 0,5 npaug ntawm qhov hnyav ntawm lub thawv, qhov ntev ntawm lub rooj tsavxwm yog ...
w_x = w sin teta
w_x = (w)(sab pem hauv ntej/hypotenuse)
0,5 (w) = (w)(2,5/x)
0,5 = (2,5/x)
x = 2,5/0,5 = 5 meters
Cov lus teb yog lawm yog A.

Qhov chaw nug lus:

Cov Lus Nug Txog Kev Xeem Thoob Tebchaws ntawm Tsev Kawm Ntawv Theem Nrab Qib Siab/Islamic Tsev Kawm Ntawv Theem Nrab Qib Siab Science