Match the following:
List-I (Metal in drinking water) | List-II (Maximum prescribed concentration in ppm) |
---|---|
A) Mn | I) \( 0.05 \) |
B) Zn | II) \( 3.0 \) |
C) Cd | III) \( 0.005 \) |
D) Cu | IV) \( 5.0 \) |
A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)):
A wooden block of mass M lies on a rough floor. Another wooden block of the same mass is hanging from the point O through strings as shown in the figure. To achieve equilibrium, the coefficient of static friction between the block on the floor and the floor itself is