A car traveling initially at +7.9 m/s accelerates uniformly at the rate of +0.72 m/s2 for a distance of 265 m. What is its velocity at the end of the acceleration? Answer in units of m/s. 10.0 points What is its velocity after it accelerates for 114 m? Answer in units of m/s

Respuesta :

Answer:

in first case velocity =21.07 m/sec in second case velocity =15.05 m/sec

Explanation:

We have given initial velocity u = 7.9 m/sec

Acceleration [tex]a=0.72m/sec^2[/tex]

Distance S = 265 m

Now according to third law of motion [tex]v^2=u^2+2as[/tex] here v is the final velocity, u is the initial velocity, a is the acceleration and s is the distance

So [tex]v^2=7.9^2+2\times 0.72\times 265=444.01[/tex]

v = 21.07 m/sec

In second case s =114 m

So [tex]v^2=7.9^2+2\times 0.72\times 114=226.57[/tex]

v =15.05 m/sec

Answer:

1. 21.07 m/s

2. 15.05 m/s

Given:

initial speed of the car, u = 7.9 m/s

distance covered by the car, d = 265 m

acceleration, a = 0.72[tex]m/s^{2}[/tex]

Solution:

To calculate the velocity at the end of acceleration, we use the third eqn of motion:

[tex]v^{2} = u^{2} + 2ad[/tex]

[tex]v^{2} = 7.9^{2} + 2\times 0.72\times 265[/tex]

[tex]v = \sqrt{7.9^{2} + 2\times 0.72\times 265} = 21.07 m/s[/tex]

Now,

Velocity after it accelerates for a distance for 114 m:

Here d = 114 m

Again, from third eqn of motion:

[tex]v^{2} = u^{2} + 2ad[/tex]

[tex]v = \sqrt{7.9^{2} + 2\times 0.72\times 114} = 15.05 m/s[/tex]