At time , how far has block moved from its original position? · OlympiadBench #1457
Physics · mechanics
Problem
At time t=1s, how far has block A moved from its original position?
Given constants:g=9.8N/kgk=1/4πϵ0=8.99×109N⋅m2/C2c=3.00×108m/sNA=6.02×1023(mol)−1σ=5.67×10−8J/(s⋅m2⋅K4)1eV=1.602×10−19Jme=9.109×10−31kg=0.511MeV/c2sinθ≈θ−θ3/6 for ∣θ∣≪1G=6.67×10−11N⋅m2/kg2km=μ0/4π=10−7T⋅m/AkB=1.38×10−23J/KR=NAkB=8.31J/(mol⋅K)e=1.602×10−19Ch=6.63×10−34J⋅s=4.14×10−15eV⋅s(1+x)n≈1+nx for ∣x∣≪1cosθ≈1−θ2/2 for ∣θ∣≪1
Extra Supplementary Reading Materials:
Collision Course
Two blocks, A and B, of the same mass are on a fixed inclined plane, which makes a 30∘ angle with the horizontal. At time t=0,A is a distance ℓ=5cm along the incline above B, and both blocks are at rest. Suppose the coefficients of static and kinetic friction between the blocks and the incline are
μA=63,μB=33
and that the blocks collide perfectly elastically. Let vA(t) and vB(t) be the speeds of the blocks down the incline. For this problem, use g=10m/s2, assume both blocks stay on the incline for the entire time, and neglect the sizes of the blocks.
Context question:
a. Graph the functions vA(t) and vB(t) for t from 0 to 1 second on the provided answer sheet, with a solid and dashed line respectively. Mark the times at which collisions occur.
Context answer:
<image_1>
Context question:
b. Derive an expression for the total distance block A has moved from its original position right after its nth collision, in terms of ℓ and n.
Context answer:
dA(n)=ℓ(2n2−2n+1)
Extra Supplementary Reading Materials:
Now suppose that the coefficient of block B is instead μB=3/2, while μA=3/6 remains the same.
Context question:
Again, graph the functions vA(t) and vB(t) for t from 0 to 1 second on the provided answer sheet, with a solid and dashed line respectively. Mark the times at which collisions occur.
Context answer:
<image_2>