Question

Children in a tree house lift a small dog in a basket 4.90m up to their house. If it takes 201J of work to do this, what is the combined mass of the dog and basket?

Answer 1

Answer:

4.18 kg.

Explanation:

Work done: Work is said to be done when ever a force move a body through a given distance. The S.I unit of work done is Joules (J)

Mathematically, work done is expressed as

W' = F×d.................... Equation 1

Where W' = work done, F = force , d = distance.

making F the subject of the equation,

F = W'/d............................. Equation 2

Note: The force need to lift the small dog n a basket = combined weight of the dog ans the basket.

Therefore,

W = F

Where W = combined weight of the dog and the basket.

Also

W = Mg

M = W/g............................. Equation 3

Where M = combined mass of the dog and the basket, g = acceleration due to gravity.

Given: W' = 201 J, d = 4.90 m.

Substitute into equation 2

F = 201/4.9

F = 41.02 N.

Since F = W = 41.02 N and g = 9.81 m/s²

Substitute these values into equation 3

M = 41.02/9.81

M = 4.18 kg.

Thus the combined mass of the dog and the basket = 4.18 kg.