Explanation:
formula: <u>Mass</u>
Density x volume
2a) m=10kg v=0.3m³
10÷0.3=33.3 kg/m
2b) m = 160 kg V=0.1m³
160÷0.1=1600 kg/m
2c) m = 220 kg V = 0.02m³
220÷0.02=11000 kg/m
A wooden post has a volume of 0.025m³ and a mass of 20kg. Calculate its density in kg/m.
density = volume ÷ mass
20÷ 0.025=800 kg/m
Challenge: A rectangular concrete slab is 0.80m long, 0.60 m wide and 0.04m thick. Calculate its volume in m³.
Formula : Length x width x height = Volume
0.80 x 0.60 x 0.04 = 0.0192m³
B) The mass of the concrete slab is 180 kg. Calculate its density in kg/m.
density = volume ÷ mass
180 ÷ 0.0192 = 9375 kg/m
Answer:
B.) by interfering with sound waves
Explanation:
As we know that the interference of sound waves is of two types
1). constructive interference
2). destructive interference
now we know that constructive interference means the resultant intensity will be more than the intensity of interfering waves as here two waves are in same phase.
In destructive interference the resultant of two waves is given by the minimum resultant of the intensity as here the phase of two waves are opposite to each other.
So we will say that
here in case of noise cancelling headphones we know that the phase of noise is always made in opposite phase with the sound which is used to cancelled the noise.
This will reduce the noise and we will get a clear sound
Answer:
c
Explanation:
betweeb the north american and eurasian planes
Answer:
A factor of 2*4 = 8
Explanation:
F_g = (G*m1*m2)/r^2
where m1 and m2 are the two masses, G is Newton's gravitational constant, and r is the distance between the center of mass of the two objects.
So, if you double m1 and quadruple m2:
m1' = 2*m1
m2' = 4*m2
Then F_g' = (G*m1'*m2')/r^2 = (G*2*m1*4*m2)/r^2 = 8*(G*m1*m2)/r^2 = 8*F_g
Answer:
2587.2 J.
Explanation:
From potential energy,
The work done to lift the chain = potential energy of the chain.
W = mgh............... Equation 1
Where W = work done to lift the chain, m = mass of the chain, g = acceleration due to gravity of the chain, h = height of the chain.
But,
m = m'd............... Equation 2
Where m' = density of the chain, d = length of the chain.
Substitute equation 2 into equation 1
W = m'dgh................ Equation 3
Given: m' = 2 kg/m, d = 12 m, h = 11 m, g = 9.8 m/s²
Substitute into equation 3
W = 2(12)(11)(9.8)
W = 2587.2 J.
