Classical Mechanics Answers

A low - frequency radio wave has a frquency of 250.000 Hz what is the wavelength of this radiowave? (Hint dont forget that is an electromagnetic wave. and therefore you should automatically know its speed.)

A wave with a frequency of 300 per second travels from water in which its velocity is 1450 m/s to air which its velocity is 331.5 m/s. Calculate the wavelengths in each medium

A longitudinal wave of frequency 100Hz has a wavelength of 11 m Find the speed of propagation.

calculate the speed of sound in air at stp. density of air at STP = 1.293 kg/m^3, y = 1.40

find the velocity of a longitudinal wave in a brass rod whose density is 8.5 g/cm^3

Find the velocity of a transverse wave in a string which is 4.0 m long with a mass with a total mass of 20 g when under a tension of 100N

An object has a positive velocity and a decreasing kinetic energy, which of the following could apply to this situation?

(a) It has a positive position moving toward the origin under a negative net force.

(b) It has a negative position moving away from the origin under a negative net force.

(c) It has a negative position moving toward the origin with a positive acceleration.

(d) It has a positive position moving away from the origin and speeding up.

(e) It has a negative position moving toward the origin and slowing down.

Which of the following is ALWAYS true?

(a) An object with a positive net force acting on it has an increasing kinetic energy.

(b) An object with a constant non-zero net force has a changing kinetic energy.

(c) If an object has a constant kinetic energy, its velocity is also constant.

(d) If an object has a constant kinetic energy the net force acting on it is zero.

(e) If an object's kinetic energy is constant, then the object's acceleration is zero.

A 2.6 kg block, in contact with a 90 N/m spring compressed by 2 m, is moving at 4.5 m/s along a ledge 5 m above the surface of the Earth, which is the zero reference level. What is the total energy of the block, as the system?

(a) 127.4 J (b) 180 J (c) 153.7 J (d) 333.7 J (e) 26.3 J

A 44 kg block is moving at 6.5 m/s at the bottom of a rough 22-degree incline. If the coefficient of friction on the incline is 0.16, what distance up along the incline does the block travel?

(a) 33.7 cm (b) 76.5 cm (c) 14.6 m (d) 80.8 cm (e) 145 cm

A 7.4 kg cart initially moving at 3 m/s is pushed for 1.4 m by a net force of 22 N. How fast will the cart be moving when the force stops acting?

(a) 2.9 m/s (b) 6.8 m/s (c) 7.5 m/s (d) 4.2 m/s (e) 3.9 m/s

A particle of mass m moves under the influence of gravity along the helix z =kθ, r =constant, where k is a constant and z is vertical. Obtain the Hamiltonian equations of motion.

A particle of mass m is attracted to a force center with the force of magnitude k/ r². Use plane polar coordinates and find Hamilton's equations of motion.