Answer:
7.888m
Explanation:
Given:
frequency 'f'= 90Hz
velocity of the sound 'v' = 340 m /sec
The wavelength of the wave is given by,
λ= v/f => 340/90
λ= 3.777m
The destructive interference condition is givn by
Δd=
λ
where, m=0,1,2,3,..
m=0, for minimum destructive interference
Δd=
x 3.777
Δd=1.888
Therefore, the required distance is
=
+ Δd => 6 + 1.888
= 7.888m
Thus, So the speaker should be placed at 7.888 m
Answer:
a ave = ( v1x - v0x ) i/Δt + v1y j/Δt
Explanation:
Answer:
400 years
Explanation:
The equation that describes the decay of a radioactive sample is:
(1)
where
m(t) is the amount of sample left at time t
is the initial amount of the sample
is the half-life, which is the time taken for the sample to halve
In this problem we have:
is the half-life of Nickel-63
After a time t, the amount of sample left is 6.25% of the original one, which means that

So we can rewrite the equation (1) and solving for t to find the time:

Answer:
F = 150.6 N
Rx = 63.65 N
Ry = - 115.5 N
orientation is - 61.14 degree with horizontal
Explanation:
given data
moment arm m = 2 cm
angel = 115 degree
distance = 13 cm
force = 21 N
to find out
muscle force, vertical component force , horizontal component force , orientation
solution
we consider here Ra and Rb is reaction upside and
we know moment formula that is
moment at joint = F × sin(θ) × m - force × distance
0 = F × sin(115) × 2 - 21 × 13
F = 150.6 N
so
for horizontal component
sum of horizontal force = Rx + Fcosθ
0 = Rx + (150.6) cos115
Rx = 63.65 N
and
for vertical component
sum of vertical force = Ry + Fsinθ
0 = Ry + (150.6) sin(115)
Ry = - 115.5 N
and
reaction direction are
tan∅ = Ry / Rx
tan∅ = -115.5 / 63.65
∅ = - 61.14 degree
so orientation is - 61.14 degree with horizontal