What is the minimum energy needed to change the speed of a 1600-kg sport utility vehicle from 15.0 m/s to 40.0 m/s?
A) 1.10 MJ
B) 40.0 kJ
C) 10.0 kJ
D) 0.960 MJ
E) 20.0 kJ

Question

Quizplus · Accepted Answer

The minimum energy needed can be calculated using the kinetic energy formula: $KE = \frac{1}{2}mv^2$, where $m$ is the mass and $v$ is the velocity. The change in kinetic energy ($\Delta KE$) gives the energy needed. For the initial speed ($v_i = 15.0 \, m/s$) and final speed ($v_f = 40.0 \, m/s$), the change in kinetic energy is $\Delta KE = \frac{1}{2} \times 1600 \times (40.0^2 - 15.0^2) = 1,100,000 \, J$ or $1.10 \, MJ$.

What Is the Minimum Energy Needed to Change the Speed