You have a particularly great party at your house while your parents are gone fo

Question

You have a particularly great party at your house while your parents are gone for the weekend. Unfortunately, two party crashers had too many shots of Jameson whiskey and drew stick animals on your walls with mud from their shoes. You attempt to clean the walls with a broomstick and a heavy wet sponge of 80 N. You use the broomstick to apply an external force of 120 N along the line of the stick as shown. This moves the sponge from rest up the wall that we will assume is frictionless. (a) How long does it take the sponge to move 1.2 m? (b) Calculate the normal force actng on the sponge. 35°

Explanation / Answer

along vertical

gravitational force Fg = -m*g = -80 N

mass m = 80/10 = 8 kg

component of force Fy = F*cos35 = 120*cos35 = 98.3 N

net force F = Fy + Fg = m*a

m*a = Fy - m*g

a = (Fy - m*g)/m

a = (98.3-80)/8

a = 2.3 m/s^2

displacement y = 1.2 m

acceleration ay = 2.3 m/s^2

initial velocity voy = 0

y = voy*t + (1/2)*ay*t^2

1.2 = (1/2)*2.3*t^2

time taken t = 1.02 s

--------------------

part (b)

along horizontal

Fnet = 0

Fx - Fn = 0

normal force Fn = F*sin35 = 120*sin35

Fn = 68.8 N <<<<------ANSWER

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.