Question

A car of mass 800 kg travels over a hill of height h. By travelling to the top of the hill, the car gains 40000 J of gravitational potential energy. The gravitational field strength g is 10 N /kg​

Answer 1

`\sf\huge{\underline{\underline{\overbrace{Answer}}}}`

The height of the hill is 5m.

Step-by-step explanation:

Given :-

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Mass of the car (m) = 800kg

Height of the hill (h) = ?

Gravitational field strength (g) = 10N/kg

Potential energy (P.E.) = 40,000J

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To find :-

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The height of the hill

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Solution :-

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⠀⠀⠀ ⠀⠀■ Note

The gravitational potential energy is the energy acquired by the object when the mass of the object is under the gravitational pull of the earth. It is directly proportional to mass and height of the object. If the mass or the height of the object increases the potential energy also increases.

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⠀⠀⠀⠀⠀□ Example

If we keep a book on the table and if we push the book from the table. This will result in the falling of the book on ground due to gravitational pull of the earth of it's mass and height.

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While formula to find potential energy is

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`\tt{\Large {P.E. = mg}}h`

But we need to find 'h'

so the formula for 'h' will be

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`\bold{\Large {h = (P.E. )/(mg) }}`

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Now substituting the required values.

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`\sf \hookrightarrow h = (40000)/(800 * 10) \\ \\ \\ \sf \hookrightarrow h = \frac{40 \cancel 0 \cancel 0 \cancel 0}{8 \cancel 0 \cancel 0 * \cancel{10}} \\ \\ \\ \sf \hookrightarrow h = \frac{ \cancel{ 40} \: \:{ \small{5}}}{ \cancel 8} \\ \\ \\ \boxed {\hookrightarrow h = 5m}`