Answer:
v = 8.8 m /s
Explanation:
For listener and source going away from each other the formula of Doppler effect is as follows
V is velocity of sound , v is velocity of listner and source of sound
f₀ is apparent frequency and f is real frequency
V = 343 , v = ? ,f = 210 , f₀ = 221
Put these value in the relation above
![[tex]\frac{210}{221} = \frac{343-v}{343+v}](https://tex.z-dn.net/?f=%5Btex%5D%5Cfrac%7B210%7D%7B221%7D%20%3D%20%5Cfrac%7B343-v%7D%7B343%2Bv%7D)
[/tex]
v = 8.8 m /s
Answer:
1.6 m/s
Explanation:
First you need to find the momentums of each disc by multiplying their velocities with mass.
disc 1: 7*1= 7 kg m/s
disc 2: 1*9= 9 kg m/s
Second, you need to find the total momentum of the system by adding the momentums of each sphere.
9+7= 16 kg m/s
Because momentum is conserved, this is equal to the momentum of the composite body.
Finally, to find the composite body's velocity, divide its total momentum by its mass. This is because mass*velocity=momentum
16/10=1.6
The velocity of the composite body is 1.6 m/s.
Kinetic energy is the energy possessed by an object when that object is moving in space. The higher the mass of an object or higher the speed of an object the higher the kinetic energy will be.
So to calculate the Kinetic Energy we can use the following formula
K.E=(1/2)*m*v^2
Inserting the values in formula gives:
K.E=1/2*7.26*2^2
14.52J
This is the final answer which gives the kinetic energy of the ball.
Answer:
<em>a) 3.6 ft</em>
<em>b) 12.4 ft</em>
Explanation:
Distance between mirrors = 6.2 ft
difference from from the mirror you face = 1.8 ft
a) you stand 1.8 ft in front of the mirror you face.
According to plane mirror rules, the image formed is the same distance inside the mirror surface as the distance of the object (you) from the mirror surface. From this,
your distance from your first "front" image = 1.8 ft + 1.8 ft = <em>3.6 ft</em>
b) The mirror behind you is 6.2 - 1.8 = 4.4 ft behind you.
the back mirror will be reflected 3.6 + 4.4 = 8 ft into the front mirror,
the first image of your back will be 4.4 ft into the back mirror,
therefore your distance from your first "back" image = 8 + 4.4 = <em>12.4 ft</em>
-- The acceleration due to gravity is 32.2 ft/sec² . That means that the
speed of a falling object increases by an additional 32.2 ft/sec every second.
-- If dropped from "rest" (zero initial speed), then after falling for 4 seconds,
the object's speed is (4.0) x (32.2) = <em>128.8 ft/sec</em>.
-- 128.8 ft/sec = <em>87.8 miles per hour</em>
Now we can switch over to the metric system, where the acceleration
due to gravity is typically rounded to 9.8 meters/sec² .
-- Distance = (1/2) x (acceleration) x (time)²
D = (1/2) (9.8) x (4)² =<em> 78.4 meters</em>
-- At 32 floors per 100 meters, 78.4 meters = dropped from the <em>25th floor</em>.
The 5 points are certainly appreciated, but I do wish they were Celsius points.
