Question

kinetic energy is calculated using the formula $ke = \frac{1}{2}mv^{2}$.

Explanation:

Step1: Calculate KE for m=2kg, v=30m/s

$KE=\frac{1}{2}mv^2=\frac{1}{2}\times2\times30^2=900J$ (Note: No match in options, maybe typo? Assuming correct pairings below)

Step2: Calculate KE for m=0.4kg, v=2m/s

$KE=\frac{1}{2}\times0.4\times2^2=0.8J$

Step3: Calculate KE for m=20kg, v=25m/s

$KE=\frac{1}{2}\times20\times25^2=6250J$

Step4: Calculate KE for m=1.1kg, v=1.1m/s

$KE=\frac{1}{2}\times1.1\times1.1^2\approx0.66J$

Step5: Calculate KE for m=0.7kg, v=3.1m/s

$KE=\frac{1}{2}\times0.7\times3.1^2\approx3.3J$

Answer:

m=2kg, v=30m/s → (No matching option shown); m=0.4kg, v=2m/s → KE=0.8J; m=20kg, v=25m/s → KE=6250J; m=1.1kg, v=1.1m/s → KE=0.66J; m=0.7kg, v=3.1m/s → KE=3.3J