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Answer 1

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=1.0¡Á10³ kg/m³¡Á10N/kg¡Á(741m£­733m)

= 8¡Á10⁴ Pa¡­................................................................1·Ö

£¨2£©P= Fv

=400N¡Á0.2 m/s¡Á4

=320W................................................................................. 1·Ö

G =F_¸¡=r_Ë®gV_ÅÅ

=1.0¡Á10³ kg/m³¡Á10N/kg¡Á0.1m³

= 10³ N...............................................................................1·Ö

W_ÓÐ = Gh

 = 10³ N¡Á2m

= 2¡Á10³ J          

          W_×Ü =Fs

 = 400N¡Á4¡Á2m

= 3.2¡Á10³ J ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­.. 1·Ö

¦Ç = W_ÓÐ/W_×Ü

= 2¡Á10³ J/3.2¡Á10³ J

             = 62.5% ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­1·Ö

 

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