An electron (mass = 9.11 X 10-31 kg) leaves one end of a TV picture tube with zero initial speed and travels in a straight line to the accelerating grid, which is 1.80 cm away. It reaches the grid with a speed of 3.00 X 106 m/s. If the accelerating force is constant, compute (a) the acceleration; (b) the time to reach the grid; and (c) the net force, in newtons. Ignore the gravitational force on the electron.

Solution 16E Step 1 of 4: Given data, 31 Mass of electron, m= 9.11 × 10 kg Initial velocity, v =i Final velocity, v =3 × 10 m/s 6 f Distance, s= 1.8 cm 2 2 Using 1 cm =10 m s= 1.8× 10 m Step 2 of 4: If the accelerating force is constant, compute (a) the acceleration; Using kinematic equation, 2 2 v f = vi + 2as 2 2 Solving for acceleration, a = vf v i 2 s 6 2 Using v =0i v =3 ×f10 m/s and s= 1.8× 10 m (3 ×10 m/s) 0 a = 2 2 (1.8×10 m) 7 2 a =8.33× 10 m/s Therefore, the acceleration of the electron is 8.33× 10 m/s . 7 2