Step-by-step explanation:
It is given that,
Speed of the proton,
![v=3.6* 10^5\ m/s](https://img.qammunity.org/2020/formulas/physics/college/qfdb5gokkoi03oyochu72yc22ke2wpcjp0.png)
Electric field,
![E=9.4* 10^3\ N/C](https://img.qammunity.org/2020/formulas/physics/college/a607bgny5ovgnuirty3fo9gq1k0j6oi75a.png)
(a) Distance covered, d = 4 cm = 0.04 m
Let t is the time interval required for the proton to travel 4.00 cm horizontally. It can be calculated as :
![t=(d)/(v)](https://img.qammunity.org/2020/formulas/physics/high-school/2uhls8dvr6edbvppie50lxbkk0x0mrjqrz.png)
![t=(0.04)/(3.6* 10^5)](https://img.qammunity.org/2020/formulas/physics/college/yy8cpiy8cevy2dq7vk65peoac4b7rzjca4.png)
![t=1.11* 10^(-7)\ s](https://img.qammunity.org/2020/formulas/physics/college/ve3gkm5ighz6qvqendj6ufps7f54zz4mvy.png)
or
t = 111 ns
(b) Since, initial speed = 0 in vertical direction. So,
So, q E = ma
![a_y=(E_yq)/(m)](https://img.qammunity.org/2020/formulas/physics/college/tjw8scws0aa5abzl1jgh95n4joqlflkvx5.png)
Displacement is given by :
![y=ut+(1)/(2)a_yt^2](https://img.qammunity.org/2020/formulas/physics/college/ahcrxeork9ef20pf0uispxaw16epvo52aa.png)
![y=(1)/(2)(E_yq)/(m)t^2](https://img.qammunity.org/2020/formulas/physics/college/fuauggcc4j0d558brqct1wrgcd9f5msucu.png)
![y=(1)/(2)* (9.4* 10^3* 1.67* 10^(-19))/(1.67* 10^(-27))(1.11* 10^(-7))^2](https://img.qammunity.org/2020/formulas/physics/college/qs68adg7kjmflyt4knqrr3qpmqimxmz01x.png)
![y=0.00579\ m](https://img.qammunity.org/2020/formulas/physics/college/rsq5sjfyikv986ehwghh5hiuq83hwrx4p1.png)
(c) For vertical component of velocity, use equation of kinematics as :
(d = 4 cm)
![v=\sqrt{2(E_yq)/(m)d_y}](https://img.qammunity.org/2020/formulas/physics/college/2v04yfiy1s4h7d5l1b6710be3sw3w4ku9r.png)
![v=\sqrt{2* (9.4* 10^3* 1.67* 10^(-19))/(1.67* 10^(-27))* 0.04}](https://img.qammunity.org/2020/formulas/physics/college/q3hw0vn3446evbdigrgejrnplvw90svbrr.png)
![v=2.74* 10^5\ m/s](https://img.qammunity.org/2020/formulas/physics/college/dnlezeyi7x4vih9riizu6h8olivrw8eac5.png)
For horizontal component of velocity,
![v_x=(d)/(t)](https://img.qammunity.org/2020/formulas/physics/college/dko6t6nr4uqlmc42e4esmnbhchfx791bps.png)
![v_x=(0.04)/(1.11* 10^(-7))](https://img.qammunity.org/2020/formulas/physics/college/2wsgcn2ngu461wscqjp4tmglqk7vwlyr6d.png)
![v_x=3.6* 10^5\ m/s](https://img.qammunity.org/2020/formulas/physics/college/z1gbrj91shygcq9vdc7cqf81zzdurjiilg.png)
Hence, this is the required solution.