Physics Answers

An Over Damped harmonic oscillator satisfied the equation (d²x/dt²)+(10dx/dt)+16x=0. At time t=0 the particle is projected from the point x=1 towards the origin with the speed "U". Find x(t) in subsequent motion.

A car travelling at 100.0 km/h sounds its horn as it approaches a hiker standing on the    highway. If the car’s horn has a frequency of 440 Hz and the temperature of the air is 0°C, what is the frequency of the sound waves reaching the hiker 

(a) as the car approaches? 

(b) after it has passed the hiker?

A radio-controlled model airplane is being flown at 48.3 km/h. if the plane is being flown at Mach 0.040, what is the temperature of the air, to the nearest degree?

1. A crest of a water wave requires 5.2 s to travel between two points on a fishing pier located 

19 m apart. It is noted in a series of waves that 20 crests pass the first point in 17 s. What is the wavelength of the waves?

A jet is flying at a speed of 356 m/s in an air temperature of 25.0 C. What is the Mach number of the jet

A plane is travelling at Mach 0.58.  If the local speed of sound is 300 m/s, what is the airspeed of the plane, in kilometers per hour?

The D string of a guitar is stretched to a tension of 150 N. The string has a mass of 3.4 g and is stretched to a length of 0.69 m. What is the speed of waves on the string

Which of the following six functions represent a travelling wave pulse whose shape does not change with time?

1. 2e^-5(x-300t)2
2. (2t-5x)³
3. 9x²-42xt+49t²
4. x²-49t²
5. sqrt[(3t-5x)²+5]
6. (5+2x-3t)/(5+2x+3t)

An object weighs 294.9N on a planet where the acceleration due to gravity is 4.9m/s². What is its weight (in N) on earth?

1.)How much energy is lost by 20 kg copper if it is cooled from 50℃ to 30℃?

2.)A 20 kg metal rod is heated 100oC with 2000 J of energy. What is the specific heat of the metal?