Question

A stationary mass explodes into two parts of mass 4 units and 40 units respectively. If the larger mass
has an initial KE. 10 J, what is the initial kinetic energy of the
smaller mass?​

Answer 1

Explanation:

=pm=−Pm=−MVm=−M2K/M√m=−2MK√m=−2(40kg)(10J)√4kg=−52–√ms

Answer 2

Given info : A stationary mass explodes into two parts of mass 4 units and 40 units respectively. If the larger mass has an initial KE is 10 J.

To find : the initial kinetic energy of the smaller mass is ...

solution : according to conservation of linear momentum,

initial momentum = final momentum

⇒0 = P₁ + P₂

⇒|P₁| = |P₂| [ it means linear momentum for both fragments are same.

but we know, P = √2Km

where K is kinetic energy and m is mass

so, |P₁| = √(2K₁m₁)

|P₂| = √(2K₂m₂)

⇒√(2K₁m₁) = √(2K₂m₂)

⇒K₁/K₂ = m₂/m₁

here K₁ = 10J, m₁ = 40 units , m₂ = 4 units

⇒10/K₂ = 4/40

⇒K₂ = 100 J

Therefore kinetic energy of smaller is 100J