If in △PQR and △LMN, ∠P=∠M=60∘, PQ:ML=PR:MN and ∠N=55∘, then ∠Q is:
If the static friction between two surfaces P and Q is measured to be 50N, then the rolling friction between these two surfaces should most likely to be: (a) 75N (b) 45N (c) 55N (d) 65N