On the horizontal surface of a truck ( = 0.6 ) a block of mass 1 kg is placed. If the truck is accelerating at the rale of $ 5 m / s^ 2 $ then frictional force on the block will be_________ N
The frictional force can be found using the formula: \( f = \mu N \), where \( \mu \) is the coefficient of friction and \( N \) is the normal force. For a horizontal surface, the normal force \( N \) is equal to the weight of the block, \( mg \). Here, \( \mu = 0.6 \), \( m = 1 \ \text{kg} \), and \( g = 9.8 \ \text{m/s}^2 \). Thus, \( N = 1 \ \text{kg} \times 9.8 \ \text{m/s}^2 = 9.8 \ \text{N} \). The frictional force is then \( f = 0.6 \times 9.8 \ \text{N} = 5.88 \ \text{N} \). However, the maximum frictional force is \( \mu mg \), and if the truck is accelerating at \( 5 \ \text{m/s}^2 \), the frictional force required to prevent slipping is \( f = ma = 1 \ \text{kg} \times 5 \ \text{m/s}^2 = 5 \ \text{N} \). Therefore, the correct answer is 5 N.