Q1. A 1590 kg car starts from rest on a horizontal road and gains a speed of 61 km/h in 30 s (a) what is its kinetic energy at the end of the 30 s?
(b) What is an average power required of the car throughout the 30 s interval?
(c) What is an instantaneous power at the end of the 30 s interval, assuming that the acceleration is constant?
Q2. An electron is a subatomic particle (m = 9.11 x 10-31 kg) that is subject to electric forces. An electron moving in the +x direction accelerates from an initial velocity of +7.35 x 105 m/s to a final velocity of 1.69 x 106 m/s whereas travelling a distance of 0.0827 m. The electron's acceleration is because of two electric forces parallel to the x axis: = 8.98 x 10-17 N and that points in the -x direction. Find the magnitudes of (a) net force acting on electron and (b) electric force.