00:01
For this problem on the topic of electric fields, we are told that in a uniform electric field of 640 newtons per kulum, a proton is accelerated from rest.
00:10
At a later time, it has reached a speed of 1 .2 times 10 to the 6 meters per second.
00:15
We want to firstly find the acceleration of the proton, then the time that the proton takes to reach the speed, the distance that it covers in this time, as well as its kinetic energy at this time.
00:28
So firstly, the acceleration of the speed, the proton a is equal to the resultant force, which is the electrostatic one, q times e, over the mass of the proton m.
00:40
This is equal to the charge of the proton 1 .602 times 10 to the minus 19 couloms, we'll suppress the units, times an electric field strength of 600 and 40 newtons per coulom divided by the mass of the proton 1 .67 times 10 to the minus 27 kg.
01:07
This gives us the acceleration of the proton to be 6 .14 times 10 to the power 10 meters per square second.
01:26
For part b we want to find the time it takes for the proton to reach the speed.
01:32
Using kinematics, we we have the final speed vf is equal to the initial speed v i plus the acceleration times the time t...