Question

An internal explosion breaks an object, initially at rest, into two pieces: A and B. Piece A has 1.9 times the mass of piece B. The energy of 7900 J is released in the explosion.
a)Determine the kinetic energy of piece A after the explosion.
Express your answer to two significant figures and include the appropriate units.
b)Determine the kinetic energy of piece B after the explosion.
Express your answer to two significant figures and include the appropriate units.

Answer 1

Kinetic energy of pieces A and B are 2724 Joule and 5176 Joule respectively.

What is the relation between the masses of A and B?

• Let mass of piece A = Ma

Mass of piece B = Mb

• Velocities of pieces A and B are Va and Vb respectively.
• As per conservation of momentum,

Ma×Va = Mb×Vb

• Here, Ma=1.9Mb

So, 1.9Mb × Va = Mb×Vb

=> 1.9Va = Vb

What are the kinetic energy of piece A and B?

• Expression of kinetic energy of piece A = 1/2 × Ma × Va²
• Kinetic energy of piece B = 1/2 × Mb × Vb²
• Total kinetic energy= 7900J

=>1/2 × Ma × Va² + 1/2 × Mb × Vb² = 7900

=> 1/2 × Ma × Va² + 1/2 × (Ma/1.9) × (1.9Va)² = 7900

=> 1/2 × Ma × Va² ×(1+1.9) = 7900 j

=> 1/2 × Ma × Va² = 7900/2.9 = 2724 Joule

• Kinetic energy of piece B = 7900 - 2724 = 5176 Joule

Thus, we can conclude that the kinetic energy of piece A and B are 2724 Joule and 5176 Joule respectively.

Learn more about the kinetic energy here:

brainly.com/question/25959744

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