physics

A girl stand 80m away from a tall cliff and blows a whistle. If the speed of sound in air is 330ms‾¹, how long would it take for her to hear the echo of the sound?

A. 2.062s B. 0.970s C. 0.485s D. 0.242s Correct Answer: Option C C. 0.485s Explanation t = 2x/v=(2×80)/330 =0.485s

6 years ago

The sound from a vibrating tuning sound is when the tip of its stem is placed on a wooden table than when in air because?

A. the friction between the table and the tuning fork generates additional energy B. air molecules obsorb sound wave but…

6 years ago

During a thunderstorm, lightning and thunder occurred simultaneously in the atmosphere. An observer on the earth surface’s sees the lightning flash shortly before hearing the thunder. This is because the.

A. atmospheric pressure is higher at the surface than at the higher altitudes B. speed of sound is less than…

6 years ago

A magnified and virtual image of a near object is produced by?

A. prism binoculars B. astronomical telescope C. periscope D. simple microscope Correct Answer: Option D D. simple microscope

6 years ago

A man 1.8m tall stands 3m away from a pin hole camera. If the distance between the pin hole and the screen of the camera is 0.3m. Calculate the height of the image of the man produced by the camera?

A. 0.18m B. 0.50m C. 1.62m D. 18.00m Correct Answer: Option A B. 0.50m Explanation hi = ho×vu=(1.8×0.3)/3 = 0.18m

6 years ago

The image of an optical pin placed at the principal focus of a concave mirror will be formed?

A. between the principal focus and the pole B. at the centre of the curvature C. between the principal focus…

6 years ago

A wave travelling from water to glass suffers a change in its speed at the common boundary. Which of the following properties explains this observation?

A. dispersion B. refraction C. interference D. diffraction Correct Answer: Option B B. refraction

6 years ago

The basic difference between a transverse wave and a longitudinal wave travelling in the same direction in a medium is in the

A. amplitude of the wave B. wavelength of the wave C. direction of vibration of the particles of the medium…

6 years ago

The temperature of 900cm³ of an ideal gas at a pressure of 114cm Hg is 27°C. Calculate its volume at 76cm Hg and 0°C.

A. 50.0 cm³ B. 546.0 cm³ C. 659.3 cm³ D. 1228.5cm³ Correct Answer: Option D D. 1228.5cm³

6 years ago

On a basis of the kinetic theory, an increase in the temperature of a fixed volume of an ideal gas causes?

A. a increase in the number of gas molecules B. a decrease in the density of the gas C. an…

6 years ago
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