Answer: velocity of the car is 113.33m/s
Explanation:
From Doppler effect,
in the case which the source is moving towards the observer at rest
f2 = v/(v-vs) *f1
where f2 is the final observed frequency
f1 is the initial observed frequency
v = 340m/s (speed of sound in air)
vs = velocity of the source of sound.
rearranging the above equation
f2*(v - vs) = f1* v
vs = (f1* v/f2) - v
but f1 = 80Hz
f2 = 60Hz
v = 340m/s
substituting,
vs = (80 x 340)/60 - 340
vs = 453.33 - 340
vs = 113.33m/s
velocity of the car is 113.33m/s
Look at the first person’s answer. Cause I know I’m wrong
Answer:
The index of refraction of the glass is 1.3
Explanation:
Given data:
i = incident angle = 50°
r = refracted angle = 36.1°
The index of refraction according Snell´s law is:
Moment about the pivot must be equal for the seesaw to balance. Initially, the first cat and the bowl are at 2 m from the pivot.
The moment due to cat = 5.3*2 = 10.6 kg.m
The moment due to bowl = 2.5*2 = 5 kg.m
The unbalanced moment = 10.6 - 5 = 5.6 kg.m
Therefore, the 3.7 kg cat should stand at a distance x from the pivot in left to balance the 5.6 kg.m.
That is,
3.7*x = 5.6 => x = 5.6/3.7 = 1.5134 m to the left (on the side of the bowl)
<span>A bike is compound machine.This means that it is made up of a bunch of different simple machines. Screws are used to hold the pieces together. The wheel of a bicycle is a wheel and axle. The pedals are also examples of this simple machine. The pedals are attached to a lever that turns a pulley.</span>
