Question

A spring is held near a small toy cart of mass 15g. On releasing the spring. The toy cart moves forward with Kinetic energy 7.5 J. Steps to find the velocity are given below. Choose an option which has correct sequence of steps to find the velocity (i) 7.5 = 0.5 x 0.15 v2 (ii) v2 = 100. (iii) 7.5x 2x 100 = 15v2 (iv) 7.5 = 0.5 x 15 x v2​

Answer 1

$Given, m=150g=</p><p></p><p> \\ 150 \times 10 - 3kg \: \\ v=0.2ms−1</p><p>On \: releasing \: the \\ toy \\ car, the \: \\ spring \: tries \: to \\ come \: back \: to \: \\ its \: \\ uncompressed \: \\ state \: by \: \\ pushing \: the \: \\ \\ car \: away. Thus \: \\ the potential energy stored \: in the spring changes into the kinetic energy of the car.</p><p>Elastic potential energy of spring(U)=kinetic energy gained by the cart</p><p></p><p></p><p>$