A 100 N force acts horizontally on a block of 10 kg placed on a horizontal rough surface of coefficient of friction μ = 0.5. If the acceleration due to gravity (g) is taken as 10 $ms^{−2}$, the acceleration of the block (in $ms^{−2}$ ) is

A 100 N force acts horizontally on a block of 10 kg placed on a horizontal rough surface of coefficient of friction μ = 0.5. If the acceleration due to gravity (g) is taken as 10 ms−2, the acceleration of the block (in ms−2 ) is

  (a) 2.5    (b) 10     (c) 5     (d) 7.5

[NEET 2002]

\[ \sum F = ma \] \[ 100 - \mu mg = ma \] \[ 100 - (0.5)(10)(10) = (10)a \] \[ 50 = 10\hspace{2mm}a \] \[ a = 5 \, \text{m/s}^2 \]