Answer:
4.35×10⁻⁴ m
Explanation:
(a)
From wave,
v = λf...................... Equation 1
Where v = speed of sound in air, λ = wavelength of sound, f = frequency of sound.
Make λ the subject of formula in equation 1
λ = v/f................. Equation 2
Given: v = 343, f = 3.45 MHz = 3.45×10⁶ Hz
Substitute into equation 2
λ = 343/(3.45×10⁶)
λ = 99.42×10⁻⁶ m
λ = 9.942×10⁻⁵ m
(b)
using,
v' = λ'f............... Equation 3
Where v' = speed of sound in tissue, λ' = wavelength of sound in tissue.
make λ' the subject of the equation
λ' = v'/f......................Equation 4
Given: v' = 1500 m/s, f = 3.45 MHz = 3.45×10⁶ Hz
Substitute into equation 4
λ' = 1500/(3.45×10⁶)
λ' = 434.783×10⁻⁶
λ' ≈ 4.35×10⁻⁴ m.
Answer:
B.) a wheel and axle and a lever
Explanation:
P.S - The exact question is -
Given - A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance. A man pushes a wheelbarrow.
To find - Which simple machines make up a wheelbarrow?
A.) a pulley and an inclined plane
B.) a wheel and axle and a lever
C.) a pulley and a wheel and axle
D.) a lever and a wedge
Proof -
The correct option is - B.) a wheel and axle and a lever
Wheelbarrows are used to carry more goods from place to place by using minimal force as compared when goods are carried by hand.
With this machine, During hauling people can save time.
Answer:
0.0268 m
Explanation:
Draw a free body diagram of the block. There are three forces: weight force mg pulling down, buoyancy of the oil B₁ pushing up, and buoyancy of the water B₂ pushing up.
Sum of forces in the y direction:
∑F = ma
B₁ + B₂ − mg = 0
ρ₁V₁g + ρ₂V₂g − mg = 0
ρ₁V₁ + ρ₂V₂ = m
ρ₁V₁ + ρ₂V₂ = ρV
ρ₁Ah₁ + ρ₂Ah₂ = ρAh
ρ₁h₁ + ρ₂h₂ = ρh
(930 kg/m³)h₁ + (1000 kg/m³)h₂ = (968 kg/m³) (4.93 cm)
Since the block is fully submerged, h₁ + h₂ = 4.93 cm.
(930 kg/m³) (4.93 cm − h₂) + (1000 kg/m³)h₂ = (968 kg/m³) (4.93 cm)
h₂ = 2.68 cm
h₂ = 0.0268 m
Answer:
Faith, to me is almost like hope but for faith you need to believe. Some people associate the word faith with religion. But that's not it. Faith is really just a stronger term than believing someone. Like you can believe in someone but not have faith in that same person. You can have faith in someone but to do that you have to believe and trust them.
Explanation:
