P=F/S
=600N/4×10^-2 m²
=1.5×10^4 Pa
答:小张对水平地面的压强为1.5×10^4 Pa.
P=F/S
=(600N+20N)/2×10^-2 m²
=3.1×10^4 Pa
答:小张背书包行走时的压强为3.1×10^4 Pa.
P=F/S
=600N/4×10^-2 m²
=1.5×10^4 Pa
答:小张对水平地面的压强为1.5×10^4 Pa.
P=F/S
=(600N+20N)/2×10^-2 m²
=3.1×10^4 Pa
答:小张背书包行走时的压强为3.1×10^4 Pa.