Help with the code - Ultra sonic Sensor -NewPing Library

Please help me with the code, Im using arduino UNO, connected an ultra sonic sensor and buzzer. The newping library is new for me, so I want that if distance is less than 50 cm , then buzzer should be activated. I have the code here, that I wrote...

#include <NewPing.h>
#define TRIGGER_PIN 7 // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN 8 // Arduino pin tied to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 200 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

const int buzzer = 6;

void setup() {
Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results.
pinMode(buzzer, OUTPUT);
pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
delay(50);
// Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
unsigned int uS = sonar.ping(); // Send ping, get ping time in microseconds (uS).
Serial.print("Ping: ");
Serial.print(sonar.convert_cm(uS)); // Convert ping time to distance and print result (0 = outside set distance range, no ping echo)
Serial.println("cm");

if
(sonar.convert_cm(uS) < 50)
{
tone(buzzer, 1300);
delay(48);
digitalWrite(LED_BUILTIN, LOW);

}
}

And here are the errors

Arduino: 1.8.3 (Windows 10), Board: "Arduino/Genuino Uno"

Tone.cpp.o (symbol from plugin): In function `timer0_pin_port':

(.text+0x0): multiple definition of `__vector_7'

libraries\NewPing\NewPing.cpp.o (symbol from plugin):(.text+0x0): first defined here

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Whats the problem ?

Please use code tags (</> button on the toolbar) when you post code or warning/error messages. The reason is that the forum software can interpret parts of your code as markup, leading to confusion, wasted time, and a reduced chance for you to get help with your problem. This will also make it easier to read your code and to copy it to the IDE or editor. If your browser doesn't show the posting toolbar then you can just manually add the code tags:
[code]`` [color=blue]// your code is here[/color] ``[/code]
Using code tags and other important information is explained in the How to use this forum post. Please read it.

Please always do a Tools > Auto Format on your code before posting it. This will make it easier for you to spot bugs and make it easier for us to read. If you're using the Arduino Web Editor you will not have access to this useful tool. I recommend you to use the standard IDE instead.

Please remove unnecessary blank lines from your code before posting to the forum. One or two to separate code into logical sections is fine but large spaces for no reason just make for more scrolling when we're trying to read your code.

When your code requires a library that's not included with the Arduino IDE please always post a link (using the chain link icon on the toolbar to make it clickable) to where you downloaded that library from or if you installed it using Library Manger(Sketch > Include Library > Manage Libraries) then say so and state the full name of the library.

You can find an explanation of the error here:
https://bitbucket.org/teckel12/arduino-new-ping/wiki/Multiple%20Definition%20of%20"__vector_7"%20Error
The strange thing is that we expect this error when you're using the library in combination with another library that uses the same timer, such as Tone. However, your code doesn't use any other libraries so something screwy is going on. The workaround described of disabling the use of the timer functions will solve the problem.