Question

A robin in flight has 20.8 J of PE when it is 27.6 m high. What is the mass of the robin? (Unit = kg)

Answer 1

`\huge \boxed{\mathrm{0.0769 \ kg}}`

Step-by-step explanation:

`\displaystyle \sf Mass=(Potential \ energy)/(Acceleration \ of \ gravity * Height)`

`\displaystyle m=(PE)/(gh)`

`\mathrm{We \ need \ to \ find \ the \ mass.}`

`\displaystyle m=(20.8)/(9.8 * 27.6)`

`m= 0.0769`

Answer 2

`\boxed{ \bold{ \purple{0.0769 \: kg \: }}}`

Step-by-step explanation:

`\sf{Potential Energy ( P.E ) \: = \: 20.8 \: joule}`

`\sf{distance \: = 27.6 \: metre}`

`\sf{mass = }` ?

`\sf{acceleration \: due \: to \: gravity = 9.68 \: {metre \: per \: second}^(2) }`

Now, let's find the mass:

`\sf{PE \: = mass * gravity \: * \: distance}`

plug the values

⇒
`\sf{20.8 = m * 9.8 * 27.6}`

Multiply the numbers

⇒
`\sf{20.8 = 270.48 \: m}`

Swap the sides of the equation

⇒
`\sf{270.48m = 20.8}`

Divide both sides of the equation by 270.48

⇒
`\sf{ (270.48m)/(270.48) = (20.8)/(270.48) }`

Calculate

⇒
`\sf{0.0769}` kg

Hope I helped!

Best regards!!