Question

a truck of mass 5000kg accelerates from 25 m/s to 35 m/s . find the change in its kinetic energy

Answer 1

$\\ \\ K.E_{i} = \frac {1}{2} m {u}^{2} \\ \\ K.E_{i} = \frac {1}{2} \times 5000 \times 625 \\ \\ K.E_{i} = 1562500 \: J \\ \\ K.E_{f} = \frac {1}{2} m {v}^{2} \\ \\ K.E_{f} = \frac {1}{2} \times 5000 \times 1225 \\ \\ K.E_{f} = 3062500 \: J \\ \\ \delta K.E = K.E_{f} - K.E_{i} \\ \\ \delta K.E = 3062500 - 1562500 \\ \\ \delta K.E = 1500000 \: J \: \: or \: \: 1.5 \times {10}^{6} \: J$