To answer this question we first need to know the distance from the crash to the swimmer and the dock.
The distance is given by:
This means that the distance from the crash to the swimmer is:
Therefore the crash happened at 5075 meters from the swimmer.
Now, to determine the time it takes the sound to reach the deck we need to determine the speed of sound on air at that temperature, this is given by:
![v=331\sqrt[]{1+\frac{T}{273}}](https://tex.z-dn.net/?f=v%3D331%5Csqrt%5B%5D%7B1%2B%5Cfrac%7BT%7D%7B273%7D%7D)
then if the temperature is 20°C we have:
![v=331\sqrt[]{1+\frac{20}{273}}=342.91](https://tex.z-dn.net/?f=v%3D331%5Csqrt%5B%5D%7B1%2B%5Cfrac%7B20%7D%7B273%7D%7D%3D342.91)
Then it takes the sound to reach the deck:
Finally to determine the time it takes after you hear it we subtract the time it takes for you to hear it, then:
Therefore your friend hear the crash 11.3 seconds after you do.
Answer:
V = 48.49m/s
Explanation:
Given the following information:
Combined mass = 92kg
Hill's height = 120m
Course of ride = 384m
Frictional force = 261N
Initial speed (u) = 9m/s
Final speed (v) = ?
Since we are looking for her speed at the bottom,
Time = distance/speed = 384m/9m.s
Time = 42.67s
we use the equation
H = V²/2g ( equation for maximum heigh of trajectory)
Therefore, plugging the values we have
120 = V²/2×9.8
V² = 9.8×120×2
V = √2352
V = 48.49m/s
I would go with b because the seasons are caused by the tilt of Earth axis, not greenhouse gases
Given:
= 12 m/s
Time = 15 s
To find:
Deceleration = ?
Formula used:
Deceleration is given by,
a = 
Solution:
Acceleration of the body is rate of increase of velocity. Deceleration of the body is negative acceleration i. e rate of decrease of velocity.
Thus, deceleration of the body is given by,
a =
where a is the deceleration of the body
v is the velocity
is rate of change of velocity
t is the time
a = 
a = 0.8 m/ 
Thus, deceleration is 0.8 m/ .
