Answer:
0.903 seconds
Explanation:
To find how many seconds the acorn fall, we can use the formula for distance travelled with constant acceleration:
D = Vo*t + a*t^2/2,
where D is the distance travelled, Vo is the inicial speed, t is the time and a is the acceleration.
In our problem:
Vo = 0,
a = g = 9.81 m/s2,
D = 4 meters.
So, we can solve the equation to find the time:
4 = 0*t +9.81*t^2/2
4.905*t^2 = 4
t^2 = 4/4.905 = 0.8155
t = 0.903 seconds
Answer:
a) The car was moving at a speed of 
b) The negative sign of 
denotes that the observer is coming towards the police car which is the source of the sound.
c) 
Explanation:
Given:
- original frequency of the source,
- speed of the source,
- velocity of the obstacle car be,
- speed of sound,
- observed frequency,
<u>Using the equation from the Doppler's effect:</u>
a)
The car was moving at a speed of
b)
The negative sign of denotes that the observer is coming towards the police car which is the source of the sound.
c)
Now when, 
Then, 
Using the Doppler's eq.:
The molecular geometry of both F2 and HF is linear.There are only two atoms which are covalently bonded and thus, the bonding scheme with the atoms looks like this;
F --- F
H---F
So, both are linear.
Answer:
The minimum work per unit heat transfer will be 0.15.
Explanation:
We know the for a heat pump the coefficient of performance (
) is given by
where, 
is the magnitude of heat transfer between cyclic device and high-temperature medium at temperature 
and 
is the required input and is given by 
, 
being magnitude of heat transfer between cyclic device and low-temperature 
. Therefore, from above equation we can write,
Given, 
and 
. So, the minimum work per unit heat transfer is given by
