Answer:
129 km/hr
Explanation:
Distance of Car A North of the Intersection, y=0.3km
Distance of Car B West of the Intersection, x=0.4 km
The distance z, between A and B is determined by the Pythagoras theorem
Taking derivative of
The distance z, between the cars is changing at a rate of 129 km/hr.
Heya!
For this problem, use the formula:
s = Vo * t + (at^2) / 2
Since the initial velocity is zero, the formula simplifies like this:
s = (at^2) / 2
Clear a:
2s = at^2
(2s) / t^2 = a
a = (2s) / t^2
Data:
s = Distance = 518 m
t = Time = 7,48 s
a = Aceleration = ¿?
Replace according formula:
a = (2*518 m) / (7,48 s)^2
Resolving:
a = 1036 m / 55,95 s^2
a = 23,34 m/s^2
The aceleration must be <u>23,34 meters per second squared</u>
Answer:
The speed of the wave as it travelled through the brass bell is;
B. 4,700 m/s
Explanation:
The given parameters are;
The wavelength of the sound wave produced from the brass bell, 
= 3.5 m
The wavelength of the wave in the brass bell, 
= 47 m
The frequency of the wave in the brass bell, f = 100 Hz
The given equation for wave speed, v = f × λ
Therefore, the speed of the wave as it travelled through the brass bell, 
, is given as follows;
= f × = 100 Hz × 47 m = 4,700 m/s
The speed of the wave as it travelled through the brass bell = = 4,700 m/s
The particle has 
and 
, and is undergoing a constant acceleration of 
.
This means its position at time 
is given by the vector function,
![\implies\vec r(t)=\left[4\,\mathrm m+\left(2\dfrac{\rm m}{\rm s}\right)t-\left(1\dfrac{\rm m}{\mathrm s^2}\right)t^2\right]\,\vec\imath-\left(1\dfrac{\rm m}{\mathrm s^2}\right)t^2\,\vec\jmath](https://tex.z-dn.net/?f=%5Cimplies%5Cvec%20r%28t%29%3D%5Cleft%5B4%5C%2C%5Cmathrm%20m%2B%5Cleft%282%5Cdfrac%7B%5Crm%20m%7D%7B%5Crm%20s%7D%5Cright%29t-%5Cleft%281%5Cdfrac%7B%5Crm%20m%7D%7B%5Cmathrm%20s%5E2%7D%5Cright%29t%5E2%5Cright%5D%5C%2C%5Cvec%5Cimath-%5Cleft%281%5Cdfrac%7B%5Crm%20m%7D%7B%5Cmathrm%20s%5E2%7D%5Cright%29t%5E2%5C%2C%5Cvec%5Cjmath)
The particle crosses the x-axis when the 
component is 0 for some time 
, so we solve:
The negative square root introduces a negative solution that we throw out, leaving us with 
or about 3.24 seconds after it starts moving.
Answer
The challenge when trying to protect the environment is expensive clean energy startup cost
Explanation
In attempts to protect the environment, energy users across the globe are shifting to new renewable energy resources which are faced by the challenge of high capital cost. Renewable energy technologies are cheap to operate but very expensive to build. The perception is that renewable energy resources are risky because they require higher construction costs.
