Answer:
u₂ = 3.7 m/s
Explanation:
Here, we use the law of conservation of momentum, as follows:

where,
m₁ = mass of the car = 1250 kg
m₂ = mass of the truck = 2020 kg
u₁ = initial speed of the car before collision = 17.4 m/s
u₂ = initial speed of the tuck before collision = ?
v₁ = final speed of the car after collision = 6.7 m/s
v₂ = final speed of the truck after collision = 10.3 m/s
Therefore,

<u>u₂ = 3.7 m/s</u>
Answer:
t = 6.68 seconds
Explanation:
The acceleration of the automobile, 
Initial speed of the automobile, u = 91 km/hr = 25.27 m/s
Final speed of the automobile, v = 104 km/hr = 28.88 m/s
Let t is the time taken to accelerate from u to v. It can be calculated as the following formula as :


t = 6.68 seconds
So, the time taken by the automobile to accelerate from u to v is 6.68 seconds. Hence, this is the required solution.
Ans is <span>I. Flowing groundwater that dissolves rock , such as limestone</span>
The concepts necessary to solve this problem are framed in the expression of string vibration frequency as well as the expression of the number of beats per second conditioned at two frequencies.
Mathematically, the frequency of the vibration of a string can be expressed as

Where,
L = Vibrating length string
T = Tension in the string
Linear mass density
At the same time we have the expression for the number of beats described as

Where
= First frequency
= Second frequency
From the previously given data we can directly observe that the frequency is directly proportional to the root of the mechanical Tension:

If we analyze carefully we can realize that when there is an increase in the frequency ratio on the tight string it increases. Therefore, the beats will be constituted under two waves; one from the first string and the second as a residue of the tight wave, as well


Replacing
for n and 202Hz for 



The frequency of the tightened is 205Hz