Question

a force is applied on a car of mass 1800kg. 80that its spread in creases from 36km to 72km /hr find the work done​

Answer 1

Answer:

270 kJ

Explanation:

Given :

Mass ( m )  = 1800 kg

Distance ( s )  = 80

Final velocity ( v ) = 72 km / hr  or 20 m / sec

Initial velocity ( u ) = 36 km / hr  or  10 m / sec

From third equation we have ,

v² = u² + 2 a s

a = ( v² - u² ) / 2 s

Putting values here

a = ( 400 - 100 ) / 160

a = 300 / 160

a = 15 / 8  m / sec²

Now :

F = m a

F = 1800 × 15 / 8

F = 225 × 15 N

F = 3375 N

Now for work done :

W = F . s

W = 3375 × 80 J

W = 2,70,000 J

W = 270 kJ

Hence , we get answer .

Answer 2

AnswEr :

Work Done is 270 kJ.

Explanation :

• Mass ( m ) = 1800 kg

• Distance ( s ) = 80

• Initial Velocity ( u ) = 36 km / hr × 5 / 18

= 10 m / sec

• Final Velocity ( v ) = 72 km / hr × 5 / 18

= 20 m / sec

Using third Equation of Motion :

⇒ v² = u² + 2as

⇒ (20)² = (10)² + 2 × a × 80

⇒ 400 = 100 + 160a

⇒ 160a = 300

⇒ a = 300 / 160

⇒ a = 15 / 8 m / sec²

We Know the Formula of Work Done as :

⇒ W = F × s

⇒ W = ma × s [ Force = Mass × Acc. ]

⇒ W = 1800 × 15 / 8 × 80

⇒ W = 1800 × 15 × 10

⇒ W = 2,70,000 J

⇒ W = 270 kJ

჻ Work Done by Car is 270 kJ.