Problem $36$ A$3$ pts$)$

b$)$ A particle has charge $q=1C$ and mass $m=100g.$ It has an initial velocity of $v=4\mathrm{.}07\frac{m}{s}$ and a conneniet acceleration vec$(a)=(20i)\frac{m}{s^2}$ in a region in which uniform electric fields and magnetic fields are preneac.

a$)$ Another particle of same charge $q=1C$ and same mass is put in a uniform magnetic meIa $B=(0$:$-20j+1k)T.$ At time $t=0,$ the charge's velocity is given by: vec$(v)=(4$hat$()-8$hat$()+12$hat$(k))\frac{m}{s}.$

Find the force exerted on the charged particle in unit$-$vector notation. $(..\mathrm{.}6$ pts$)$

Does the magnetic force cause a change in the speed of the charge? Explain. $(.../1$ pts$)$

Does it cause a change in the angle between vec$(v)$ and vec$(B)?(.../1$ pts$)$

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$5$