Question

the table shows information about four students who are running around a track.
motion of students
which statement is supported by the information in the chart?
autumn has more kinetic energy than chiang.
mohammed has less kinetic energy than autumn
lexy has more kinetic energy than mohammed.
chiang has less kinetic energy than lexy.

Explanation:

Step1: Calculate kinetic energy for Autumn

Kinetic energy formula \(KE=\frac{1}{2}mv^{2}\). For Autumn, \(m = 50\space kg\), \(v=4\space m/s\). So \(KE_{Autumn}=\frac{1}{2}\times50\times4^{2}= 400\space J\)

Step2: Calculate kinetic energy for Mohammed

For Mohammed, \(m = 57\space kg\), \(v = 3\space m/s\). So \(KE_{Mohammed}=\frac{1}{2}\times57\times3^{2}=\frac{1}{2}\times57\times9 = 256.5\space J\)

Step3: Calculate kinetic energy for Lexy

For Lexy, \(m = 53\space kg\), \(v = 2\space m/s\). So \(KE_{Lexy}=\frac{1}{2}\times53\times2^{2}= 106\space J\)

Step4: Calculate kinetic energy for Chiang

For Chiang, \(m = 64\space kg\), \(v = 5\space m/s\). So \(KE_{Chiang}=\frac{1}{2}\times64\times5^{2}=\frac{1}{2}\times64\times25= 800\space J\)

Step5: Compare kinetic energies

• \(KE_{Autumn}=400\space J\), \(KE_{Chiang}=800\space J\) (Autumn < Chiang)
• \(KE_{Mohammed}=256.5\space J\), \(KE_{Autumn}=400\space J\) (Mohammed < Autumn)
• \(KE_{Lexy}=106\space J\), \(KE_{Mohammed}=256.5\space J\) (Lexy < Mohammed)
• \(KE_{Chiang}=800\space J\), \(KE_{Lexy}=106\space J\) (Chiang > Lexy)

Answer:

Mohammed has less kinetic energy than Autumn.