用500n水平恒力将质量为250nkg的物体,从静止开始沿水平地面推动50m历时10s.若物
1个回答

s=at²/2,s=50m,t=10s

a=1m/s

F'=250N,F=500N

f=250N

μ=f/G=f/mg=250N/(250kg由S=1/2at^2,可得:a=2S/t^2=2*50/10^2=1m/s^2

由F-f=ma,可得:f=F-ma=500-250*1=250N *10N/kg)=0.1 1/2at²=50,a=1

F-f=ma,f=250