Physics Test Grade 8

Test your Grade 8 physics knowledge on waves and motion!

Type your full name: An example of a sound receiver is _: vocal cords tuning fork loudspeaker all of the above A fly flaps its wings back and forth 100 times per second.The period of the wings flapping is _: 100 seconds 100 Hz 0.01 seconds 0.01 Hz A tennis coach paces back and forth along the sideline 10 times per minute. The frequency of the pacing is _: 0.167 sec 0.167 Hz 6 Hz 60 Hz Sonar is used for exploring and mapping the oceans by sending ultrasound waves of frequency _: 15 Hz 40 Hz 15 KHz 40 KHz Which wave has the shortest wavelength? Orange wave Green wave Blue wave Purple wave A car travels from Beirut to Saida in 30 minutes and returns back in 18 minutes. The distance between Beirut and Saida is 40 km.The average speed of the car is _: 25 Km 50 Km 75 km 100 km A bus driven at 90 Km is travelling at the same speed of a car moving at _: 1.5 m 25 m 324 m 900 m Which of the following is an example of a periodic motion? The rotation of Earth about its axis The motion of the bob of a clock pendulum The revolution of Earth around the Sun All of the above Which movie has the longest duration? Movie (A) that lasts for 1 hour 30 minutes Movie (B) that lasts for 100 minutes Movie (C) that starts at 9:00 pm and ends at 10:15 pm Movie (D) that starts at 11:00 am and ends at 1:00 pm The adjacent figure shows the speedometer of a car moving in a uniform rectilinear motion, then_: The instantaneous and average speeds have the same value of 50 Km The instantaneous speed is 50 Km and the average speed is zero The average speed is 50 Km and the instantaneous speed is zero The instantaneous and average speeds are zero A wave of frequency of 250 Hz and wavelength of 8 m will travel at a speed of _: 0.032 m 31.25 m 1000 m 2000 m Which statement describes a sound wave? It is a transverse wave that can propagate in vacuum It is a transverse wave that can’t propagate in vacuum It is a longitudinal wave that can propagate in vacuum It is a longitudinal wave that can’t propagate in vacuum Referring to the figure, which statement is True? The wavelength of the wave is 4 cm The wavelength of the wave is 8 cm The amplitude of the wave is 4 cm The amplitude of the wave is 8 cm The adjacent figure shows a student using a Slinky to produce a wave. The slinky is stretched at one end. A wave travels along the slinky and its loops vibrate back and forth. This is an example of a _: Longitudinal wave where energy and matter are transferred Longitudinal wave where only energy is transferred Transverse wave where energy and matter are transferred Transverse wave where only energy is transferred The pendulum is in periodic vibratory motion. As it completes one oscillation, it passes by the equilibrium position B _: Once Twice Three times Four times A 5 Hz wave travelling at a speed of 10 m has a period of _: 0.2 sec 0.5 sec 2 sec 50 sec A point that represents a crest of a wave is _: B C D E In a given medium, the frequency of a sound waves decreases. Which of the following statements is true? The period of the sound waves decreases The period of the sound waves remains the same The speed of the sound waves decreases The speed of the sound waves remains the same As a car moves along a highway, its covered distance is recorded at equal time intervals as shown in the table. Which statement describes the motion of the car? The car is moving with no acceleration The car is uniformly accelerated motion The car is uniformly decelerated motion The car is at rest A horizontal rope is connected from one of its extremities to a vibrating blade. A wave propagates from the right to left of the rope. A snapshot of the rope is shown in the figure. Which statement is true? The source of disturbance producing the wave is the rope and it is placed at point A The source of disturbance producing the wave is the rope and it is placed at point C The source of disturbance producing the wave is the vibrating blade and it is placed at point A The source of disturbance producing the wave is the vibrating blade and it is placed at point C