(1)你后半部分算错了,v≠at*t
应该是a=dv/dt=d√(8t)/dt=√(2/t)
另外,a=√2*at=2√2*t
所以√(2/t)=2√2*t
2/t=8t^2
t^3=1/4
t=(1/4)^(1/3)
(2)位移s=∫(0,(1/4)^(1/3)) vdt
=∫(0,(1/4)^(1/3)) √(8t)dt
=(4√2)/3*t^(3/2)|(0,(1/4)^(1/3))
=(2√2)/3
sin(Δθ/2)=(s/2)/R
=(√2)/12
Δθ=2arcsin[(√2)/12]
没任何问题 很好狠正确
(1)
v = ∫(0, t) at dt = ∫(0, t) 2t dt = t^2
an = v^2/R = t^4 / 4
an = at 时, t^4 / 4 = 2t,得
t = 2 s
(2)
Δθ = (1/R) ∫(0, 2) v dt
= (1/4) ∫(0, 2) t^2 dt
= 2/3 rad