brained10
contestada

2. A car starts from rest and accelerates uniformly to
reach a speed of 21 m/s in 7.0 s. What was the speed of
the object after 2.0 seconds?​

Respuesta :

Answer:

speed of object after 2 seconds will be 6 ms⁻¹

Explanation:

Initial velocity = 0

Final Velocity = 21 m/s

Time = 7 sec

We need to find speed of object after 2.0 seconds.

First we will find acceleration using formula: [tex]Accelaration=\frac{change \ in \ velocity}{change \ in \ time}[/tex]

Putting values:

[tex]Accelaration=\frac{Change \ in \ velocity}{Change \ in \ time}\\Accelaration=\frac{21-0}{7}\\Accelaration=\frac{21}{7}\\Accelaration= 3 \ ms^{-2}[/tex]

Now finding speed of object after 2 seconds

The formula used will be: [tex]Speed(v) = a\times t+v_0[/tex]

Putting values of a= 3m/s², t=2 sec and v₀=0 (at rest)

[tex]Speed(v) = a\times t+v_0\\Speed(v) = 3\times 2+0\\Speed(v) =6\ ms^{-1}[/tex]

So, speed of object after 2 seconds will be 6 ms⁻¹