Physics V

A block is attached to a spring that is oscillating at 5 Hz, it has an amplitude of 0.25 meters. After 15 seconds, what is the position from the normal?

• 0.23 meters to the left of the normal position

• 0.09 meters to the left of the normal position

• 0.09 meters to the right of the normal position

• 0.23 meters to the right of the normal position

A spring that is fixed at one end oscillates with a frequency of 11Hz and an amplitude of 0.2m. What is the period of the spring?

• 1/11 s

• 1/22 s

• 1/44 s

• 1/66 s

A weft is stretched as shown in the following figure and four pendulums are attached to the weft. After swinging the leftmost pendulum P for a while, choose the correct one for each of the remaining three pendulums A, B and C. However, assume that the swing of P, the first to swing, is not very large.

• Only A swings.

• Only B swings.

• Only C swings.

• Both A and B swing.

• A, B and C all swing.

As shown in the figure, waves of the same wavelength and phase are emitted from two distant points A and B on the water surface. The red line in the figure represents the wave front of the mountain and the blue line represents the wave front of the valley. Do the waves get stronger or weaker at points C, D and E? Answer the correct combination.

• C: Weaker

  D: Stronger

  E: Stronger

• C: Weaker

  D: Weaker

  E: Stronger

• C: Weaker

  D: Stronger

  E: Weaker

• C: Stronger

  D: Stronger

  E: Weaker

• C: Stronger

  D: Weaker

  E: Stronger

A source of sound approaches a stationary observer at a speed of 20 m/s. Choose all the following sentences that correctly describe the phenomenon that occurs at this case.

• The speed of sound is different before and after the sound source.

• The wavelength is different in front of and behind the sound source.

• The frequency of the sound heard by the observer remains constant as the source approaches.

• As the source approaches, the sound heard by the observer becomes higher and higher.

A source of sound approaches a stationary observer at a speed of 20 m/s. Find the frequency of the sound heard by the observer, assuming that the frequency of the sound source is 800 Hz and the speed of sound is 340 m/s.

• 711 Hz

• 756 Hz

• 800 Hz

• 850 Hz

• 900 Hz

If a sound at a frequency of 500 Hz and a sound at a frequency of 502 Hz are played simultaneously, how many beats per second can we hear?

• 1 time

• 2 times

• 3 times

• 4 times

• 5 times

A pulse wave travels to end point Q as shown in the figure. If point Q is a fixed end, select the correct waveform after reflection.

• A

• B

• C

As shown in the figure, there is a sinusoidal wave travelling in a positive direction on the x-axis. Now the wave has a hill at x = 3.0 m. It took 0.50 s for the wave to travel and for the position at x = 3.0 m to become a hill. Find the speed of the wave.

• 3.0 m/s

• 6.0 m/s

• 9.0 m/s

• 12.0 m/s

• 15.0 m/s

What type of wave is a longitudinal wave? Choose the correct one from the following options.

• Waves travelling vertically

• Waves in which the medium oscillates vertically

• Waves in which the direction in which the wave travels and the direction in which the medium oscillates are parallel.

• Waves in which the direction in which the wave travels and the direction in which the medium oscillates are perpendicular.