Answer:
Explanation:
In the first case you can use the expression for the Doppler effect when the source is getting closer and getting away
( 1 )
( 2 )
f' = perceived frequency when the source is getting closer
f'' = perceived frequency when the source is getting away
f = source frequency
v = relative speed
vs = sound speed
by dividing (1) and (2) you have
but this is the relative velocity, you have that
a. hence, the speed of the police car is 102.5m/s
Answer:
The horizontal forces are equal in size and opposite in direction. They are balanced, so the horizontal resultant force is zero. This means that there is no horizontal acceleration just a horizontal constant speed. If a submarine is not moving horizontally, then there are no horizontal forces.
I hope it helps.
Answer: The total resistance in a parallel circuit is always less than any of the branch resistances. Adding more parallel resistances to the paths causes the total resistance in the circuit to decrease. As you add more and more branches to the circuit the total current will increase because Ohm's Law states that the lower the resistance, the higher the current.
Explanation:
Answer: 2.70 cm
Given:
Density, 
Mass, m=184 g
Formula Used:
Volume, V = density/mass
where a is the side of the cube
hence, the length of one side of silver cube is 2.70 cm
Using kinematics: 8.1 = 1/2(9.8)(t^2),
t = 1.2857 s.
Horizontal distance x travelled is x = vhorizontal * t, so 9.3 = v*1.2857, or v= 7.233 m/s horizontally.
