Find the magnitude of Q and show that Q makes an angle of 120° with P.相关知识点: 试题来源: 解析 P^2+Q^2-2PQcos θ =P^2, giving Q^2=2PQcosθ4P^2+Q^2-4PQcos θ =3P^2, giving P^2+Q^2=4PQcos θP^2+Q^2=2^2, hence Q=P; θ =60^( ° )反馈 收藏 ...
Let the resultant of P and Q be R1, and that of P and -Q be R2. R1 =P +Q, R2 =P -Q, R_1^2=R_1⋅R_1=(P+Q)⋅(P+Q) =P^2+Q^2+2P⋅Q where Q = 2P (given). But P and Q are perpendicular, so P . Q =0. Therefore R =P2 +4P2 = 5P2 and R1=√5P....
The main tool for investigating excitations is theτdependence of the Euclidean correlation function of several operators (‘Two-times observables’ inMethods). It is crucial to distinguish even operators (such as\(P\,{\mathcal{A}}P={\mathcal{A}}\)) from odd operators (\(P\,{\mathcal{...
Moreover, it can be seen that the minimization of 2tr((YYT−(AAYYT+bb11T))WW1(YYT−(AAYYT+bb11T))T +2λtr(AAWW2AAT) forces ‖((YYT−bb11T)−AA(YYT−bb11T))c‖2 and ‖(AA)c‖2 to be very small when WW2 and WW1 are large. Finally, some columns of (YYT−bb...
Electrical contact is an essential issue for all devices. Although the contacts of the emergent two-dimensional materials have been extensively investigated, it is still challenging to produce excellent contacts. The face and edge type contacts have been
In the general case µ and η depend on the fluid pressure p and temperature T, which in turn depend on x. Therefore the couple stress length l defined by Eq. (2) depends on x. The space derivative of the function f in the Reynolds Eq. (1) is:(3)dfdx=Cdhdx−DVTdTdx−DVp...
Previous studies have demonstrated a high level of sequence divergence in P. gigantea hydrophobin-encoding genes Pgh1 and Pgh2[20] and the hydrophobins from the pathogenic fungus H. irregulare Hah1 and Hah2[12]. These observations raised crucial questions on the evolutionary forces driving the ...
Section B-|||-Passage One-|||-(9)Many people enjoy secret codes.The harder the code,the more some people will try to figure it out.-|||-In wartime,codes are especially important.They help army send news about battles and the size of enemy-|||-forces.Neither side wants its code bro...
Formation mechanisms of two-dimensional nanostructures in wet syntheses are poorly understood. Even more enigmatic is the influence of hydrodynamic forces. Here we use liquid flow cell transmission electron microscopy to show that layered double hydroxid
respectively, the initial and final configurations at each relaxation step. The force is applied along the lattice-adirection. The red dashed arrows indicate the direction of thet2g-porbital interaction. The hollow blue arrows show the resulting movement of the X and M2atoms within the Q–X–...