12 A 60 kg ice-skater, travelling initially at \( 3.0 \mathrm{~m} / \mathrm{s} \), glides across a horizontal icy surface. The skater brakes and comes to rest after 5.0 m . The work done against the braking force is the change in the kinetic energy of the skater. What is the braking force? 18 N A 27 N

An economist conducted a study of the possible association between weekly income and weekly grocery expenditures. The particular interest was whether higher income would cause shoppers to spend more on groceries. A random sample of shoppers at a local supermarket was obtained. A questionnaire was administered asking about the weekly income of each shopper's family and their grocery bill for that week. The gender of each shopper was also obtained. The relationship between grocery expenditure and income was assessed by calculating both a correlation for the females only and a correlation for the males only. For the females, \( r=0.45 \) and for the males, \( r=0.38 \). We conclude that: the relationship between grocery expenditures and income is the same for males and females. there is not enough information to determine which gender has a stronger relationship between grocery expenditures and income. the relationship between grocery expenditures and income is stronger for females. the relationship between grocery expenditures and income is stronger for males.

\( x-\frac{1}{x}=1: \) :

[6] If \( (2-i) \) is one of the roots of the equation: \( x^{2}-4 x+k=0 \), then \( k=\ldots \) (a) 3 (b) -3 (c) 5 (d) -5

1. \( 5 \sqrt{81}= \) 2. \( \sqrt{8^{2}+6^{2}}= \)

\( A=-2, B=-3, C=-4, D=5 \) find \( \Rightarrow 3 B C D= \)