LASHAE06
contestada

A skateboard chsnges velocity from 15 meters per second to 5 meters per second, over the course of 5 seconds. What is the skateboards acceleration?
A. -2 m/s^2
B. +2 m/s^2
C. +0.5 m/s^2
D. -0.5 m/s^2​

Respuesta :

Option A) is correct.

We are given –

  • Initial velocity of skateboard is, u= 15m/s
  • Final velocity of skateboard is,v = 5 m/s
  • Time taken, t = 5 sec
  • Acceleration, a =?

Formula To be used:-

[tex]\qquad[/tex] [tex]\star\: \: \pink{\boxed{\frak{ a = \dfrac{(v-u)}{t}}}}[/tex]

Where–

  • A = Acceleration
  • v = Final velocity
  • u = Initial velocity
  • t = time

[tex]\qquad\qquad\quad\underline{\sf{Substituting \ Values \ :}}[/tex]

⠀⠀⠀━━━━━━━━━━━━━━━━━━━━━━━━━━

[tex]\qquad[/tex][tex] \bf \longrightarrow a = \dfrac{v-u}{t}[/tex]

[tex]\qquad[/tex][tex] \sf \longrightarrow a = \dfrac{5-15}{t}[/tex]

[tex]\qquad[/tex][tex] \sf \longrightarrow a = \dfrac{-10}{5}[/tex]

[tex]\qquad[/tex][tex] \sf \longrightarrow a = \cancel{\dfrac{-10}{5}}[/tex]

[tex]\qquad[/tex][tex]\pink{ \bf \longrightarrow a = -2 \:m/s^2}[/tex]

  • Henceforth, acceleration is -2 m/s².

Answer:

-2 m/s²

Explanation:

Here it's given that a skateboard changes its velocity from 15m/s to 5m/s in an interval of 5s . We are interested in finding out the acceleration of the skateboard. Firstly we know that,

  • The rate of change of velocity is called acceleration. Mathematically,

[tex]\qquad\rm\twoheadrightarrow accl^n =\dfrac{v - u }{t} [/tex]

Here ,

  • initial velocity = 15m/s
  • final velocity = 5m/s
  • time = 5s

On substituting the respective values, we have;

[tex]\qquad\rm\twoheadrightarrow accl^n =\dfrac{5m/s-15m/s}{5s}[/tex]

Simplify numerator,

[tex]\qquad\rm\twoheadrightarrow accl^n =\dfrac{-10m/s}{5s}[/tex]

Divide,

[tex]\qquad\rm\twoheadrightarrow \underline{\boxed{\blue{\rm acceleration= -2\ m/s^2}}} [/tex]

Therefore, Option A is correct choice.