Answer:
where is the answers ??
is there any answer called upward pointing arrow .
No, it can also be less than 1 depending on the class of the lever.
Answer:
YES
Explanation:
An echo may be defined as a sound which is repeated because of the sound waves that are produced are reflected back after striking a surface. Sound waves can smoothly bounce off the hard objects in the same manner as a rubber ball bounces back the ground.
When a sound wave strikes a hard surface, the sound waves gets reflected back and bounces back to the observer and produces an echo. If the sound waves strikes a soft surface it absorbs the sound.
Although the direction of a sound changes but the echo sounds in the same way as the original sound.
Displacement = velocity * time
Just substitute the value, & solve the equation.
Hope this helps!
