Physics Gravitation Level: Misc Level
Gravitation between Earth and Moon
The mass of the Earth is given as 5.98. 10 24 kg, our Moon, s mass as 7.35. 10 22 kg, the The average distance as 3.84. 108 m, and G=6.673. 10-11 Nm2 /kg2 is the gravitational constant.
a) Compute the force with which Earth attracts our Moon and compute the force with which our Moon attracts Earth. Compare the results and comment on them.
b) Compute the accelerations of Earth and Moon toward each other. Compare the results and reason why we consider that our Moon orbits Earth.
c) If gravitation was the only physics happening to our Moon, it and Earth would collide after about 6 days. What prevents our Moon from crashing into Earth?
Physics Force & Laws Of Motion Level: Misc Level
Helicopter A
Three forces act on a helicopter that's flying at a speed of 100 km/h to the right: its; weight is 53, 800 N( determine its mass as well), it exerts a lift force of 58,900 N at an angle of 69 % from the positive horizontal, and it experiences air resistance along the negative horizontal of 21,100 N.
a) Make a drawing with all force vectors, label them too.
b) Write down Newton,s law in vector from.
c) Determine the total force and determine the acceleration.
Physics Force & Laws Of Motion Level: Misc Level
Car in a banked curve
Make a drawing of a car driving through a frictionless banked curve.Draw in all force vectors and label them. Write down Newton,s law pertaing to this scenario.
Physics Force & Laws Of Motion Level: Misc Level
Astronaut
Suppose an astronaut is taking a space walk to fix his spacecraft with a hammer. His life-line breaks and the jet packs on his backpack are out of fuel.Explain how can he return safely to his spaceship (without someone else,s help)?
Physics Force & Laws Of Motion Level: Misc Level
Boat on the Water
A person sits in boat, having a paddle and other gear. The boat is slowly moving along in the middle of a lake. Apply each of Newton,s 3 laws in terms of what could happen to the boat, the person, the paddle, the water.
Physics Gravitation Level: Misc Level
Stars originate as larges bodies of slowly rotating gas. Because of gravity, these clumps of gas slowly decrease in size. The angular velocity of a star increases as it shrinks because of?
Physics Gravitation Level: Misc Level
Halley, s comet moves about the sun in an elliptical orbit with its closest approach to the sun being 0.59 A.U. and its furthest distance being 35 A.U. (1 Astronomical Unit is the Earth -sun distance). If the comet, s speed at closest approach is 54 km/s, what is its speed when it is farthest from the sun?
Physics Rotational Mechanics Level: Misc Level
A particle whose mass is 3 kg moves in the xy plane with a constant speed of 4 m/s along the direction r=i+j . what is the angular momentum in (kg x m^2 /s) realtive to the point (0,4.0) meters?
Physics Waves And Oscillations Level: Misc Level
A piano string of length 1.50 m and mass density 26.0 mg/m vibrates at a ( fundamental) frequency of 450.0 Hz.
(a) What is the speed of the transverse string waves? m/s
(b) What is the tension? N
(c) What are the wavelength and frequency of the sound wave in air produceed by vibration of the string? The speed of sound in air at room temperature is 340 m/s. m Hz
Physics Waves And Oscillations Level: Misc Level
Two waves with identical frequency but different amplitudes A1=6.0 cm and A2=3.0 cm, occupy the same regin of space( are superimposed).
(a) At what phase difference does the resulting wave have the largest amplitude?What is the amplitude of the resulting wave in that case? cm
(b)At what phase difference does the resulting wave have the smallest amplitude and what is its amplitde? cm
Physics Wave Optics Level: Misc Level
Light of wavelength 0.512 um (in air) enters the water in a swimming pool. The speed of lihgt in water is 0.730 times the speed in air. What is the wavelength of the light in water?nm
Physics Waves And Oscillations Level: Misc Level
The speed of sound in air at room temperature is 338 m/s.
(a) What is the frequency of a sound wave in air with wavelength 2.5 m? Hz
(b) What is the frequency of a radio wave with the same wavelength? ( Radio waves are electromagnetic waves that travel at 3.0x 108 m/s in air or in vacuum.) Hz
Physics Waves And Oscillations Level: Misc Level
A uniform string of length 10.0 m and weight 0.35 N is attached to the ceiling.A weight of 1.00 kN hangs from its lower end. The lower end of the string is suddenly displaced horizontally. How long does it take the resulting wave pulse to travel to the upper end? [ Hint: Is the weight of the string negligible in comparison with that of the hanging mass?] ms
Physics Waves And Oscillations Level: Misc Level
A uniform string of length 10.0 m and weight 0.35 N is attached to the ceiling.A weight of 1.00 kN hangs from its lower end. The lower end of the string is suddenly displaced horizontally. How long does it take the resulting wave pulse to travel to the upper end? [ Hint: Is the weight of the string negligible in comparison with that of the hanging mass?] ms
Physics Waves And Oscillations Level: Misc Level
A uniform string of length 10.0 m and weight 0.35 N is attached to the ceiling.A weight of 1.00 kN hangs from its lower end. The lower end of the string is suddenly displaced horizontally. How long does it take the resulting wave pulse to travel to the upper end? [ Hint: Is the weight of the string negligible in comparison with that of the hanging mass?] ms
