Ask Barry Allen he’s the faster man alive
I think you divide so 2 sorry I’m wrong
A distance of d is covered with 53 mile/hr initially.
Time taken to cover this distance t1 = d/53 hour
Next distance of d is covered with x mile hours.
Time taken to cover this distance t2 = d/x hours.
We have average speed = 26.5 mile / hour
= Total distance traveled/ total time taken
= ![\frac{2d}{\frac{d}{53}+\frac{d}{x}} = \frac{2}{\frac{1}{53}+\frac{1}{x} } = \frac{106x}{x+53}](https://tex.z-dn.net/?f=%5Cfrac%7B2d%7D%7B%5Cfrac%7Bd%7D%7B53%7D%2B%5Cfrac%7Bd%7D%7Bx%7D%7D%20%3D%20%5Cfrac%7B2%7D%7B%5Cfrac%7B1%7D%7B53%7D%2B%5Cfrac%7B1%7D%7Bx%7D%20%7D%20%20%3D%20%5Cfrac%7B106x%7D%7Bx%2B53%7D)
![26.5 = \frac{106x}{x+53} \\ \\ 79.5 x = 1404.5\\ \\ x = 17.67 miles/hour](https://tex.z-dn.net/?f=26.5%20%3D%20%5Cfrac%7B106x%7D%7Bx%2B53%7D%20%5C%5C%20%5C%5C%2079.5%20x%20%3D%201404.5%5C%5C%20%5C%5C%20x%20%3D%2017.67%20miles%2Fhour)
Answer:
![\boxed {\boxed {\sf 56.25 \ Joules}}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%2056.25%20%5C%20Joules%7D%7D)
Explanation:
Kinetic energy can be found using the following formula:
![E_k=\frac{1}{2}mv^2](https://tex.z-dn.net/?f=E_k%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2)
where <em>m </em>is the mass and <em>v</em> is the velocity.
The mass of the ball is 0.5 kilograms and the velocity is 15 meters per second
![m= 0.5 \ kg \\v= 15 \ m/s \\](https://tex.z-dn.net/?f=m%3D%200.5%20%5C%20kg%20%5C%5Cv%3D%2015%20%5C%20m%2Fs%20%5C%5C)
Substitute the values into the formula.
![E_k=\frac{1}{2} (0.5 \ kg ) * (15 \ m/s)^2](https://tex.z-dn.net/?f=E_k%3D%5Cfrac%7B1%7D%7B2%7D%20%280.5%20%5C%20kg%20%29%20%2A%20%2815%20%20%5C%20m%2Fs%29%5E2)
First, evaluate the exponent.
- (15 m/s)²= (15 m/s) * (15 m/s) = 225 m²/s²
![E_k=\frac{1}{2} (0.5 \ kg ) *(225 \ m^2/s^2)](https://tex.z-dn.net/?f=E_k%3D%5Cfrac%7B1%7D%7B2%7D%20%280.5%20%5C%20kg%20%29%20%2A%28225%20%5C%20m%5E2%2Fs%5E2%29)
Multiply 0.5 kg by 225 m²/s²
![E_k=\frac{1}{2}(112.5 \ kg* m^2/s^2)](https://tex.z-dn.net/?f=E_k%3D%5Cfrac%7B1%7D%7B2%7D%28112.5%20%5C%20kg%2A%20m%5E2%2Fs%5E2%29)
Multiply 112 kg*m²/s² by 1/2, or divide by 2.
![E_k=56.25 \ kg*m^2/s^2](https://tex.z-dn.net/?f=E_k%3D56.25%20%5C%20kg%2Am%5E2%2Fs%5E2)
- 1 kg*m²/s² is equal to 1 Joule
- Therefore, our answer of 56.25 kg*m²/s² is equal to 56.25 Joules.
![E_k= 56.25 \ J](https://tex.z-dn.net/?f=E_k%3D%2056.25%20%5C%20J)
The kinetic energy of the ball is <u>56.25 Joules</u>
The answer is A.
Hope I helped.