A 2,200 kg car moving at 18 m/s hits a barrier and comes to a stop. How much work is done to bring the car to a stop?3.6 x 105J3.6 x 105J4.2 x 105J4.2 x 105J

Respuesta :

Answer:

[tex]3.6 \times {10}^{5}J[/tex]

Explanation:

From the question, mass(m)=2200kg, unitial velocity(u)=18m/s and final velocity(v)=0m/s

We can calculate the work done to bring the car to a stop from the relation;

[tex]W = F \times S........eqn(1)[/tex],where

W=Work done

F=Force

S=distance

Also,

[tex]F = m \times a............eqn(2)[/tex]

Putting eqn(2) into equn(3) we obatin

[tex]W = m \times a \times S......eqn(3)[/tex]

From the equation of motion;

[tex]a= \frac{v - u}{t}[/tex]

and

[tex]S = (\frac{u + v}{2})t[/tex]

Substituting these into eqn(3), we obtain;

[tex] W =m \times ( \frac{v - u}{t}) \times ( \frac{u + v}{2})t[/tex]

[tex] \implies W=m \times ( v - u) \times (u + v)\times\frac{t}{t} \times \frac{1}{2} [/tex]

[tex]\implies W=m \times ( v - u\times (u + v)\times \frac{1}{2} [/tex]

Substituting the values of m,u and v into the equation, we obtain.

[tex]\implies W=2200 \times ( 0 - 18) (18+ 0)\times \frac{1}{2} [/tex]

Simplifying, we obtain;

[tex]\implies W=1100 \times - 18 \times 18[/tex]

[tex]\implies W= - 356400 = - 3.564 \times {10}^{5} [/tex]

NB: The negative sign indicates that the car decelerated to a stop.

Hence the Work done on the car is

[tex]3.6 \times {10}^{5}J[/tex]

The work done on the car will be "3.6 × 10⁵ J".

Work done

According to the question,

Mass, m = 2200 kg

Initial velocity, u = 18 m/s

Final velocity, v = 0 m/s

As we know,

→ Work done (W) = Force(F) × Distance(S) ...(equation 1)

or,

→ Force(F) = Mass(m) × Acceleration(a) ...(equation 2)

From "equation 1" and "equation 2", we get

→ Work done(W) = m × a × S ...(equation 3)

By using Equation of motion,

a = ([tex]\frac{v-u}{t}[/tex])

and,

S = ([tex]\frac{v+u}{2}[/tex])t

Substituting "a" and "S" in "equation 3", we get

→ W = m × ([tex]\frac{v-u}{t}[/tex]) × ([tex]\frac{v+u}{2}[/tex])t

       = m × (v-u) × (v+u) × [tex]\frac{t}{t}[/tex] × [tex]\frac{1}{2}[/tex]

       = m × (v-u) × (v+u) × [tex]\frac{1}{2}[/tex]

By substituting the values,

       = 2200 × (0-18) (0+18) × [tex]\frac{1}{2}[/tex]

       = 1100 × (-18)(18)

       = -3.564 × 10⁵ or,

       = 3.6 × 10⁵ J  

Thus the response above is appropriate.

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https://brainly.com/question/25573309