In everyday language, power and force are similar, but in physics ()
A. force has only magnitude.
B. power has only direction.
C. force has magnitude and direction.
D. power has magnitude and direction.
E. None of these answers are correct.
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The radius of a circle is increased by 5%. The percentage increase of the circumference is ()
A. 5%.
B. 10%.
C. 12%.
D. 16%.
E. 20%
The electron configuration of element 25 is [Ar] 3d54s2, then it is in ( ) period of periodic table.
A. 2
B. 3
C. 4
D. 5
If 180 g glucose (M=180 g/mol) is dissolved in 1 kg water. The magnitude of freezing point depression of this solution is ( ). (Kf=1.86 K•kg•mol-1)
A. 0.512 K
B. 1.86 K
C. 1.024K
D. 3.72K
What mass of NaCl is contained in 500 mL of a 0.200 mol/L NaCl solution?
A. 11.7 g
B. 5.85 g
C. 75 g
D. 58.5 g