An ice sled powered by a rocket engine starts from rest on a large frozen lake and accelerates at 12.7 m/s2 . At t1 the rocket engine is shut down and the sled moves with constant velocity v for another t2 s. The total distance traveled by the sled is 5.85 × 103 m and the total time is 94.6 s. Find t1. Answer in units of s.

Respuesta :

Answer:

The value of t₁ is 5.119 sec.

Explanation:

Given that,

Acceleration = 12.7 m/s²

Total distance [tex]D=5.85\times10^{3}\ m[/tex]

Time = 94.6 sec

We need to calculate the distance

Using equation of motion

[tex]s=ut+\dfrac{1}{2}at^2[/tex]

Put the value into the formula

[tex]s_{1}=0+\dfrac{1}{2}12.7t_{1}^2[/tex]...(I)

We need to calculate the velocity

Using equation of motion

[tex]v=u+at[/tex]

Put the value into the formula

[tex]v=0+12.7t_{1}[/tex]

[tex]v=12.7t_{1}[/tex]

The sled while moves with constant velocity v for time t₂

Using formula of distance

[tex]s_{2}=vt_{2}[/tex]

[tex]s_{2}=12.7t_{1}t_{2}[/tex]

The total distance is

[tex]s_{1}+s_{2}=5.85\times10^{3}[/tex]

Put the value of s₁ and s₂

[tex]\dfrac{1}{2}12.7t_{1}^2+12.7t_{1}t_{2}=5.85\times10^{3}[/tex]

[tex]6.35t_{1}+12.7t_{1}t_{2}=5.85\times10^{3}[/tex]...(II)

The total time is

[tex]t_{1}+t_{2}=94.6[/tex]....(III)

From equation (II) and (III)

After solving

[tex]t_{1}=5.119\ sec[/tex]

Hence, The value of t₁ is 5.119 sec.