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