Question
While moving into your new place, you have to push a 25-kg box across the foor. Yotu push on it with some force at angle of 27 below your shoulder, as shown in the figure. Assuming the coetlicient of static friction between the box and floor is 0.60, with what force do you nexi to push to just get the box moving? (Hint:it is safe to assuune that the aeceleration of the box is still zero at the instant it starts moving.) 5 t (EP) A heavy crate (23 kg) is resting on a frictionless inclined plane while suspended from a wall by a spring. The plane is inclined at an angle of 30° from the horizontal, and the spring is stretched from its equilibrium position by 25 cm. What is the spring constant of the spring? If the frictionless inclined plane i now replaced with an otherwise identical plane except with a rough surface, the crate now stretel spring by 12 cm from its equilibrium position. What is the coetlicient of static friction? You can assume th the static friction is at its maximum value. hes the sdt
Explanation / Answer
(9) Here normal reaction, R = mg = 25*9.81 N
So, frictional force, Ff = u(s)*R = 0.60*25*9.81 N
Suppose force applied by me is F Newton.
Now force applied by me in the horizontal direction, Fx = F*cos27 N
So, for the condition of the box just to start moving -
F*cos27 N = 0.60*25*9.81 N
=> F = (0.60*25*9.81) / cos27 = 165.15 N
