Total time in between the dropping of the stone and hearing of the echo = 8.9 s
Time taken by the sound to reach the person = 0.9 s
Time taken by the stone to reach the bottom of the well = 8.9 - 0.9 = 8 seconds
Initial speed (u) = 0 m/s
Acceleration due to gravity (g) = 9.8 m/s^2
Time taken (t) = 8 seconds
Let the depth of the well be h.
Using the second equation of motion:

h = 313.6 m
Hence, the depth of the well is 313.6 m
Answer:
Part(a): The angular acceleration is
.
Part(b): The angular displacement is
.
Explanation:
Part(a):
If
be the initial angular speed, final angular speed and angular acceleration of the centrifuge respectively, then from rotational kinematic equation, we can write

where '
' is the time taken by the centrifuge to increase its angular speed.
Given,
,
and
. From equation (
), the angular acceleration is given by

Part(b):
Also the angular displacement (
) can be written as

Yes this is not gonna work
Answer:
F = 1618.65[N]
Explanation:
To solve this problem we use the following equation that relates the mass, density and volume of the body to the floating force.
We know that the density of wood is equal to 750 [kg/m^3]
density = m / V
where:
m = mass = 165[kg]
V = volume [m^3]
V = m / density
V = 165 / 750
V = 0.22 [m^3]
The floating force is equal to:
F = density * g * V
F = 750*9.81*0.22
F = 1618.65[N]
Answer:
Honda won by 0.14 s
Explanation:
We are given that
Distance =S=200 m
Initial velocity of Honda=u=0m/s
Initial velocity of Porsche=u'=0m/s
Acceleration of Honda=
Acceleration of Porsche's=
Time taken by Honda to start=1 s

Substitute the values




Time taken by Honda=11.55 s
Now, time taken by Porsche



Total time taken by Porsche=10.69+1=11.69 s
Because it start 1 s late
Time taken by Honda is less than Porsche .Therefore, Honda won and
Time =11.69-11.55=0.14 s
Honda won by 0.14 s