T=1/v=1/0,8=1,25 c
N=t/T=15/1,25=12
S=4*xm*N=4*2*12=96 см
К( кило) 10^3
1) 5,2 × 10^3 м = 5,2км
м( мили) 10^-3
2) 1,8 × 10^-3 м = 1,8мм
Массы тел равны.
E=mV²/2
E₂ /E₁ =V₂²/V₁² =(V₂/V₁)² =(20/10)²=2² =4
Ответ: у второго тела Ek больше в 4 раза, чем у первого тела.
<span>Дано:</span>
<span>t</span>1=2<span>c</span>
<span>V</span>1=5<span>м</span>/<span>c</span>
<span>t</span>2=3<span>c</span>
<span>V2=7</span><span>м</span><span>/c</span>
<span>Vcp-?</span>
<span>Vcp=S/t, <span> </span>S=S1+S2, t=t1+t2</span>
<span>S1=V1*t1,<span> </span>S1=5*2=10</span><span>м</span>
<span>S2=V2*t2,<span> </span>S2=7*3=21</span><span>м</span>
<span>S</span><span>=10м+21м=31</span><span>м</span>,<span> </span><span>t</span>=2<span>c</span>+3<span>c</span>=5<span>c</span>
<span>Vcp</span>=31/5=6,2м/с