Answer:
8.85m/s
Explanation:
The potential energy the watermelon held before dropping is Ep=mgh=2*9.8*4=78.4J.
When it strikes the ground, all of its Ep will transfer into Ek, so 1/2*m*v^2=78.4.
We already knew that m=2, so insert that in, we will get the V^2=78.4 m/s, V=8.85 m/s
This is because Newton refined Galileo's idea of inertia and created it as his first law of motion. Galileo stated that it was the propensity of things to resist changes in motion. Newton refined it by including: "Every thing continues in a condition of rest or uniform speed in a straight line except acted on by a nonzero net power".
Answer:
t = 22.2 s
Explanation:
angular distance covered in the 36.0 s is
θ = ω(avg)t = ½(10.0 + 30.0)36 = 720 radians
720/2 = 360 radians
α = Δω/t = (30 - 10)/36 = 5/9 rad/s²
θ = ω₀t + ½αt²
360 = 10.0t + ½(5/9)t²
0 = (5/18)t² + 10.0t - 360
0 = t² + 36t - 1296
t = (-36 ±√(36² - 4(1)(-1296))) / 2
t = (-36 ±√(6480)) / 2
t = -18 ±√1620
we ignore the negative time result as it occurs before we care.
t = -18 + √1620 = 22.249223... s
The question is incomplete. The complete question is :
Two loudspeakers are placed 1.8 m apart. They play tones of equal frequency. If you stand 3.0 m in front of the speakers, and exactly between them, you hear a minimum of intensity. As you walk parallel to the plane of the speakers, staying 3.0 m away, the sound intensity increases until reaching a maximum when you are directly in front of one of the speakers. The speed of sound in the room is 340 m/s.
What is the frequency of the sound?
Solution :
Given :
The distance between the two loud speakers, 
The speaker are in phase and so the path difference is zero constructive interference occurs.
At the point 
, the speakers are out of phase and so the path difference is 
Therefore,
Thus the frequency is :
Hz
The only evidence you have that you exist as a self-aware being is your conscious experience of thinking about your existence. Beyond that you're on your own. You cannot access anyone else's conscious thoughts, so you will never know if they are self-aware.
