Question

A force of 750 n is applied to a block of mass 102 kg to prevent it from sliding on a plane with an inclination angle 300 with the horizontal. If the coefficients of static friction and kinetic friction between the block and the plane are 0.4 and 0.3 respectively, then the frictional force acting on the block is

Answer 1

Answer:

dynamic friction

Explanation:

if the kinetic energy is less than the static energy then the object is moving

let's find the Normal reaction force of an object

$r = 1020 \cos(30) \\ 1020 \frac{ \sqrt{3} }{2} \\ = 888.32n$

$staticfrictio = co - efficient \times r \\ 0.4 \times 888.32 \\ 355.328n$

kinetic friction

and also let's find the kinetic friction

$kf = co - efficient \times r \\ = 0.3 \times 888.32 \\ = 266.496n$

in here kinetic friction is less than the static friction

this means object is moving

therefore the friction used in here is kinetic friction....