Answer:
7.1 J
Explanation:
From the question,
Work done by the mover = work done in pushing the crate + work done against friction
W = W'+Wf................. Equation 1
W = mgd+mgμd............ Equation 2
W = mgd(1+μ)................ Equation 3
Where m = mass of the crate, g = acceleration due to gravity, d = distance, μ = coefficient of friction.
Given: m = 46 kg, d = 10.5 mm = 0.0105 m, μ = 0.5
constant: g = 9.8 m/s²
Substitute these values into equation 3
W = 46×9.8×0.0105(1+0.5)
W = 7.1 J
Answer:
330.24 Hz
Explanation:
Given:
Frequency, f = 320 Hz
L1 = 25.8 cm
L2 = 78.4 cm
L3 = 131.1 cm
Let the wavelength be λ
Then, L1 which is the length of the column of air is λ/4.
λ/4 = 25.8 cm
λ = 25.8 × 4 = 103.2 cm = 1.032 m
Then, speed of sound in air is:
v = λ f
⇒ v = 1.032 × 320 Hz
⇒ v = 330.24 m/s
Answer is b hope this helps