Kepler's second law of planetary motion<span> describes the speed of a </span>planet<span> traveling in an elliptical orbit around the sun. It states that a line between the sun and the </span>planetsweeps equal areas in equal times. Thus, the speed of theplanet<span> increases as it nears the sun and decreases as it recedes from the sun.</span>
A black hole forms when the center of a very massive star collapses in upon itself.
Answer: 26.84 m/s
Explanation:
Given
Original frequency of the horn 
Apparent frequency 
Speed of sound is 
Doppler frequency is

Where,

Insert values
![\Rightarrow 246=228\left[\dfrac{340+v_o}{340-0}\right]\\\\\Rightarrow 366.84=340+v_o\\\Rightarrow v_o=26.8\ m/s](https://tex.z-dn.net/?f=%5CRightarrow%20246%3D228%5Cleft%5B%5Cdfrac%7B340%2Bv_o%7D%7B340-0%7D%5Cright%5D%5C%5C%5C%5C%5CRightarrow%20366.84%3D340%2Bv_o%5C%5C%5CRightarrow%20v_o%3D26.8%5C%20m%2Fs)
Thus, the speed of the car is 
Initial velocity (u) = 0 m/s
Final velocity (v) = 25 m/s
time taken (t) = 10s
acceleration (a) = ?
Now,
Acceleration is rate of change of velocity, so formula is
a = (v - u)/t
a = (25 - 10)/10
a = 15/10
a = 1.5 m/(s^2)
Use this value of a.
Answer:
143 batteries does Benny need to sample
Explanation:
Given data
confidence level = 97%
error = ±10 hours
standard deviation SD = 55 hours
to find out
how many batteries does Benny need to sample
solution
confidence level is 97%
so a will be 1 - 0.97 = 0.03
the value of Z will be for a 0.03 is 2.17 from standard table
so now we calculate no of sample i.e
no of sample = (Z× SD/ error)²
no of sample = (2.16 × 55 / 10)²
no of sample = 142.44
so 143 batteries does Benny need to sample