Answer:
The angle between the inclined block and the horizontal surface is 25.16⁰
Explanation:
Given;
mass of block, m = 1.2 kg
force acting parallel to the inclined plane, F = 9 N
frictional force on the block, Fk = 2.8 N.
acceleration of the block. a = 1 m/s²
According to Newtons second law of motion, sum of all the forces acting on the block is given by;
∑F = Ma
F - W - N = ma
where;
F is the parallel force on the block, acting upwards
W is the weight of the block inclined at an angle θ, acting downwards
N is the normal reaction on the block, acting upwards = frictional force on the block.
F - mgsinθ - Fk = ma
9 - (1.2 x 9.8)sinθ - 2.8 = 1.2 x 1
6.2 - 11.76sinθ = 1.2
11.76sinθ = 6.2 - 1.2
11.76sinθ = 5
sinθ = 5 / 11.76
sinθ = 0.4252
θ = sin⁻¹ (0.4252)
θ = 25.16⁰
Therefore, the angle between the inclined block and the horizontal surface is 25.16⁰