When solving question that contains equations and the use mathematical computations, It is always ideal to list the parameters given.
Now, given that:
- the speed of the car which is the initial velocity (u) = 100 km/h before it hits the wall.
- after hitting the wall, the final velocity will be (v) = 0 km/h
Assumptions:
- Suppose we make an assumption that the distance travelled during the collision of the car with the brick wall (S) = 1 m
- That the car's acceleration is also constant.
∴
For a motion under constant acceleration, we can apply the kinematic equation:
![\mathsf{v^2 = u^2 + 2as}](https://tex.z-dn.net/?f=%5Cmathsf%7Bv%5E2%20%3D%20u%5E2%20%2B%202as%7D)
where;
v = final velocity
u = initial velocity
a = acceleration
s = distance
From the above equation, making acceleration (a) the subject of the formula:
![\mathsf{v^2 - u^2 =2as }](https://tex.z-dn.net/?f=%5Cmathsf%7Bv%5E2%20-%20u%5E2%20%3D2as%20%7D)
![\mathsf{a = \dfrac{v^2 - u^2 }{2s}}](https://tex.z-dn.net/?f=%5Cmathsf%7Ba%20%3D%20%5Cdfrac%7Bv%5E2%20-%20u%5E2%20%7D%7B2s%7D%7D)
The initial velocity (u) is given in km/h, and we need to convert it to m/s as it has an effect on the unit of the acceleration.
since 1 km/h = 0.2778 m/s
100 km/h = 27.78 m/s
![\mathsf{a = \dfrac{(0)^2 - (27.78)^2 }{2(1)}}](https://tex.z-dn.net/?f=%5Cmathsf%7Ba%20%3D%20%5Cdfrac%7B%280%29%5E2%20-%20%2827.78%29%5E2%20%7D%7B2%281%29%7D%7D)
![\mathsf{a = \dfrac{- 771.7284 }{2}}](https://tex.z-dn.net/?f=%5Cmathsf%7Ba%20%3D%20%5Cdfrac%7B-%20771.7284%20%7D%7B2%7D%7D)
a = - 385.86 m/s²
Similarly, from the kinematic equation of motion, the formula showing the relation between time, acceleration and velocity is;
v = u + at
where;
v = 0
-u = at
![\mathsf{t = \dfrac{-u}{a}}](https://tex.z-dn.net/?f=%5Cmathsf%7Bt%20%3D%20%5Cdfrac%7B-u%7D%7Ba%7D%7D)
![\mathsf{t = \dfrac{-27.78}{-385.86}}](https://tex.z-dn.net/?f=%5Cmathsf%7Bt%20%3D%20%5Cdfrac%7B-27.78%7D%7B-385.86%7D%7D)
t = 0.07 seconds
An airbag is designed in such a way as to prevent the driver from hitting on the steering wheel or other hard substance that could damage the part of the body. The use of the seat belt is to keep the driver in shape and in a balanced position against the expansion that occurred by the airbag during the collision on the brick wall.
Thus, we can conclude that the airbag must be inflated at 0.07 seconds faster before the collision to effectively protect the driver.
Learn more about the kinematic equation here:
brainly.com/question/11298125?referrer=searchResults
The fragment of an asteroid or any interplanetary material is known as a a : D. Meteroid
Human came in contact with this material mostly because it penetrate the atmosphere and fall within the earth surface
hope this helps
Answer:
The maximum height attained by the object and the number of seconds are 128 ft and 4 sec.
Explanation:
Given that,
Initial velocity u= 128 ft/sec
Equation of height
....(I)
(a). We need to calculate the maximum height
Firstly we need to calculate the time
![\dfrac{dh}{dt}=0](https://tex.z-dn.net/?f=%5Cdfrac%7Bdh%7D%7Bdt%7D%3D0)
From equation (I)
![\dfrac{dh}{dt}=128-64t](https://tex.z-dn.net/?f=%5Cdfrac%7Bdh%7D%7Bdt%7D%3D128-64t)
![128-64t=0](https://tex.z-dn.net/?f=128-64t%3D0)
![t=\dfrac{128}{64}](https://tex.z-dn.net/?f=t%3D%5Cdfrac%7B128%7D%7B64%7D)
![t=2\ sec](https://tex.z-dn.net/?f=t%3D2%5C%20sec)
Now, for maximum height
Put the value of t in equation (I)
![h =128\times2-32\times4](https://tex.z-dn.net/?f=h%20%3D128%5Ctimes2-32%5Ctimes4)
![h=128\ ft](https://tex.z-dn.net/?f=h%3D128%5C%20ft)
(b). The number of seconds it takes the object to hit the ground.
We know that, when the object reaches ground the height becomes zero
![128t-32t^2=0](https://tex.z-dn.net/?f=128t-32t%5E2%3D0)
![t(128-32t)=0](https://tex.z-dn.net/?f=t%28128-32t%29%3D0)
![128=32t](https://tex.z-dn.net/?f=128%3D32t)
![t=4\ sec](https://tex.z-dn.net/?f=t%3D4%5C%20sec)
Hence, The maximum height attained by the object and the number of seconds are 128 ft and 4 sec.
Answer:
Hearing loss due to sound energy damaging the nerve cells in the inner ear. Many animals behavior is influenced by sound energy. They learn to associate events with sounds, so they run when something crunches in the dry grass (might be a coyote), but won't be bothered by the sound of a waterfall. Mood is affected by sound energy. A wine glass can break with sound energy, if the frequency matches the resonant frequency of the wine glass and the amplitude is great enough (one Mythbusters show featured a professional singer who broke a wine glass with his voice without any amplification).
Sound energy causes the particles in the medium it is traveling through to vibrate.
Unlike sound electromagnetic waves can travel trough empty space
hope these different answers help
Answer:
13 km
Explanation:
The bird flies from the runner, to the finish line, and back to the runner. We can write two equations for the distance it travels:
d = 7.8 km + 7.8 km − 4.9 km/hr × t
d = 24.5 km/hr × t
Solve for t in the second equation and substitute into the first:
t = d / 24.5
d = 7.8 + 7.8 − 4.9 (d / 24.5)
d = 15.6 − 0.2 d
1.2 d = 15.6
d = 13
The bird flies a cumulative distance of 13 km.