Respuesta :
Answer:
A
Step-by-step explanation:
The position of an atom moving inside a cathode ray tube is given by the function:
[tex]f(t)=t^3-4t^2+3t[/tex]
Where f(t) is in meters and t is in seconds.
And we want to determine its instantaneous velocity at t = 2.5 seconds.
The velocity function is the derivative of the position function. Thus, find the derivative of the function:
[tex]f'(t)=3t^2-8t+3[/tex]
Then the instantaneous velocity at t = 2.5 will be:
[tex]f'(2.5)=3(2.5)^2-8(2.5)+3=1.75\text{ m/sec}[/tex]
Our answer is A.
Answer:
Instantaneous Velocity:
[tex]\longrightarrow\:\rm v = \dfrac{dt}{dy}[/tex]
[tex]\longrightarrow\:\rm v = \dfrac{d}{dy}( {t}^{3} - 4 {t}^{2} + 3t) \\ [/tex]
[tex]\longrightarrow\:\rm v = 3 {t}^{3 - 1} - 2.4 {t}^{2 - 1} + 3[/tex]
[tex]\longrightarrow\:\rm v = 3 {t}^{2} - 8 t + 3[/tex]
[tex]\longrightarrow\:\rm v = 3 {(2.5)}^{2} - 8 (2.5)+ 3[/tex]
[tex]\longrightarrow\:\rm v = 3 \times 6.25 - 20+ 3[/tex]
[tex]\longrightarrow\:\rm v = 18.75 - 20+ 3[/tex]
[tex]\longrightarrow\:\rm v = 18.75 - 20+ 3[/tex]
[tex]\longrightarrow\:\bf v = 1.75 \: {ms}^{ - 1} [/tex]