Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat
cliff is away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know
therefore frequency of the echo slightly decreased.
Answer:
4. both blocks will both have the same amount of kinetic energy.
Explanation:
When the blocks are released free from the compression force, the spring exerts equal and opposite force on each block but the block with heavier (double) mass will attain slower ( half ) speed as compared to the lighter block according to the law of inertia. This works in synchronization to energy conservation.
Spring force is given as:
where: length of compression in the spring
<u>We know kinetic energy is given by:</u>
Hence the kinetic energy of both the blocks is equal when they are released to move free.