Answer:
12.3 m/s
Explanation:
The Doppler equation describes how sound frequency depends on relative velocities:
fr = fs (c + vr)/(c + vs),
where fr is the frequency heard by the receiver,
fs is the frequency emitted at the source,
c is the speed of sound,
vr is the velocity of the receiver,
and vs is the velocity of the source.
Note: vr is positive if the receiver is moving towards the source, negative if away.
Conversely, vs is positive if the receiver is moving away from the source, and negative if towards.
Given:
fs = 894 Hz
fr = 926 Hz
c = 343 m/s
vs = 0 m/s
Find: vr
926 = 894 (343 + vr) / (343 + 0)
vr = 12.3
The speed of the car is 12.3 m/s.
Answer:
The resistance is 0.124 ohm.
Explanation:
It is common for domestic electrical installations to use copper wire with a diameter of 2.05 mm. Determine the resistance of such a wire with a length of 24.0 m.
diameter, d = 2.05 mm
radius, r = 1.025 mm
Length, L = 24 m
resistivity of copper = 1.7 x 10^-8 ohm m
Let the resistance is R.

Answer:
F = 352 N
Explanation:
we know that:
F*t = ΔP
so:
F*t = M
-M
where F is the force excerted by the wall, t is the time, M the mass of the ball,
the final velocity of the ball and
the initial velocity.
Replacing values, we get:
F(0.05s) = (0.8 kg)(11m/s)-(0.8 kg)(-11m/s)
solving for F:
F = 352 N
D
Using the kinetic energy 1/2mv^2 formula
5*10^5 is the answer