Question

Luyando wants to have a bit of fun with her wagon. She puts her 12 baby sister, Waluse, on the wagon and pulls it across the floor using a rope at an angle of 22° above the floor. Using the spring balance that mum uses to weigh things in the kitchen, Luyando realises that the tension in the rope is constant and has a value of about 40 . Use the work-energy theorem to find Waluse’s speed after being pulled 4.0 across the living room. The coefficient of friction is 0.2 and the weight of the wagon is 3kg

Answer 1

Answer:

work energy equation

$w.d(external)= \delta \: k.e+ \: \: \ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: w.d(ressesive)$

Explanation:

first of all we have to find reaction force to find fr

$fr = \mu \: mg \\ mg = reaction \: force(r) \\ f = ma \\ r + 40 \sin(22) - 150 = 0 \\ r = 150 - 40 \sin(22)$

then let's find friction

$fr = \mu \: r \\ 0.2 \times (150 - 40 \sin(22) )$

then let's apply work energy principle...its on the 2nd picture

v = 2.3ms^-1