Question

A 60N force is needed to start a $60$ kg skater moving across a frozen lake. The coefficient of static friction for steel on ice is approximately $(g=10m{s}^{-2})$

• A. 0.06
• B. 0.6
• C. 0.1
• D. 1

Answer 1

Answer: (C)

0.1

At $60N$ force, the skater starts moving which means the applied force equals the maximum frictional force. i.e $F=f$ $=>F=\mu mg$
$=>\mu =\frac{F}{mg}$
$\mu =\frac{60N}{60kg\times 10m{s}^{-2}}$ $=$ $0.1$