Nathanial Frost

2023-02-24

The position of a particle moving along x-axis is given by $x=(5{t}^{2}-4t+20)m$, where t is in second. Find the magnitude average velocity between 1 s and 3 s.

A)10 m/.s

B)16 m/.s

C)14 m/.s

D)5 m/.s

A)10 m/.s

B)16 m/.s

C)14 m/.s

D)5 m/.s

Haylie Long

Beginner2023-02-25Added 7 answers

The right option is B 16 m/.s

We know, $x=(5{t}^{2}-4t+20)m$

t=1 s; ${x}_{in}=5\times (1{)}^{2}-4\times (1)+20=21m$

$t=3s;{x}_{in}=5\times (3{)}^{2}-4\times (3)+20=53m$

${v}_{avrg}=\mathrm{\u25b3}x\mathrm{\u25b3}t$

${v}_{avrg}=(53-21)/(3-1)=16m/s$

We know, $x=(5{t}^{2}-4t+20)m$

t=1 s; ${x}_{in}=5\times (1{)}^{2}-4\times (1)+20=21m$

$t=3s;{x}_{in}=5\times (3{)}^{2}-4\times (3)+20=53m$

${v}_{avrg}=\mathrm{\u25b3}x\mathrm{\u25b3}t$

${v}_{avrg}=(53-21)/(3-1)=16m/s$