Answer
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
<span>A motor produces less mechanical energy than the energy it uses because the motor looses some energy to heat.</span>
A: geologist
b: physical science
c: space science
d: ecologist
Answer:a substance with low ability or no ability to conduct energy
Explanation:
Answer:
Acceleration, 
Explanation:
Initial speed of the skater, u = 8.4 m/s
Final speed of the skater, v = 6.5 m/s
It hits a 5.7 m wide patch of rough ice, s = 5.7 m
We need to find the acceleration on the rough ice. The third equation of motion gives the relationship between the speed and the distance covered. Mathematically, it is given by :




So, the acceleration on the rough ice
and negative sign shows deceleration.