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10m of rope has a mass of 2.0kg. When the speed of transverse waves along the rope is 6.0ms^-1 the tension in N is?
(a) 1.2 (b) 7.2 (c) 72.0) (d) 28.8 (e) 2880 answers
E56. The equation y= a sin (wt-kx) represents a sound wave traveling along the x-direction. What is the physical interpretation of the quantities a, y, w, t, and k? Deduce whether the wave is traveling in the positive or negative x-direction.
If a= 2.0*10^-7m, w= 8*10^3 s^-1, and k= 25m^-1 calculate (a) the speed of a particle of the wave, and (b) the maximum speed of a particle of the medium disturbed by the wave.
What is the equation of the reflected wave produced when such a wave strikes a rigid boundary normally? By considering the interference of the two waves, show that the resulting displacement is a stationary wave and deduce the distance between successive nodes.
(c) the following system may be used commercially to measure mass (or weight) (1) if, at the sensor, the maximum measurable deflection is 10mm and k= 10^5 Nm^-1, calculate the maximum measurable mass, Mmax. (2) calculate the frequency of oscillation when Mmax is applied. (3) suggest an improvement to the system to enable many measurement of mass to be made in rapid succession.
A worker pushes a wood crate of mass 23.4 kg across a concrete floor with a constant horizontal force of magnitude 80N. In a straight-line displacement of magnitude d= 1.5 m, the speed of the crate decreases from 0.90 m/s to 0.50 m/s.
Find the following:
a. Work done by the worker’s force.
b. Change in the kinetic energy of the crate.
c. The Increase in the thermal energy of the crate and the floor.
A 200 g object is whirled in a horizontal circle with a cord of radius 1.2 m at 3rev/s. The work done in doing this is.
Which requires more work: (Body A) lifting a 50.0 kg crate a vertical distance of 2.0 meters; (Body B) lifting a 25.0 kg crate a vertical distance of 4.0 meters?
A 100 kg block is pulled at a constant speed of 5 m/s across a horizontal force by an applied force of 122 N directed 37 o above the horizontal. The rate at which the force does work on the block is.
Find the average horsepower, P =? required to raise a 150 kg drum to a height of 20 m in a time of 1 minute. SOLUTION: P = wk/t = mgH/t
You push against the rock with a force of F = 100N for t = 20 seconds. If the rock does not move d = 0, how much work have you done, Wk?
SOLUTION: Wk = F d cos 0
How was water first made as the universe began, and how was it distributed without breaking the hydrogen/oxygen bonds ?
