Question

Object A has 4J of kinetic energy. Object B has twice the velocity of A but only 1/2 the mass. Therefore, the kinetic energy of object B will be:

Answer 1

Given :

• Kinetic energy of A = 4J
• Object B has twice the velocity of A but only half the mass

To Find :

• Kinetic energy of object B

Solution :

▪ Kinetic energy related with moving body is given by

$\boxed{\bf{\large{KE=\dfrac{1}{2}mv^2}}}$

• m denotes mass
• v denotes velocity

$\sf\dfrac{(KE)_A}{(KE)_B}=\dfrac{\cancel{\frac{1}{2}}m_A{v_A}^2}{\cancel{\frac{1}{2}}m_B{v_B}^2}\\ \\ \sf\dfrac{4}{(KE)_B}=\dfrac{2}{4}\\ \\ \sf {(KE)_B=\dfrac{4\times 4}{2}}\\ \\ \underline{\underline{\bf{kinetic\:energy\:of\:B=8J}}}$