Answer:
Is the sum of potential and kinetic energy in an object that is used to do work.
5 second fall starting at 0 m/s
ball strikes ground at a speed = 49 meters per second.
<h3><u>Answer;</u></h3>
Period = 1/17 seconds
<h3><u>Explanation;</u></h3>
- Wavelength is related to period by the expression:
<em>speed = wavelength / period
</em>
- If we are given the speed, then we can easily calculate the period at the wavelength of 20 m.
<em>Given the speed of sound wave as 340 m/s </em>
<em>Period = Wavelength/ speed</em>
<em> = 20 m/340 m/s</em>
<em> </em><u><em>= 1/17 seconds</em></u>
Answer:
Speed of the speeder will be 28 m/sec
Explanation:
In first case police car is traveling with a speed of 90 km/hr
We can change 90 km/hr in m/sec
So 
Car is traveling for 1 sec with a constant speed so distance traveled in 1 sec = 25×1 = 25 m
After that car is accelerating with
for 7 sec
So distance traveled by car in these 7 sec

So total distance traveled by police car = 224 m
This distance is also same for speeder
Now let speeder is moving with constant velocity v
so 
v = 28 m/sec