Answer:
1.11 m/s
Explanation:
The motion of the boat is an example of accelerated motion, since the velocity is not constant. However, we don't need to find the acceleration, because we are only interested in the average velocity of the boat, which is given by:

where d is the total distance covered and t the time taken. In this problem, the boat covered a distance of d = 20 m and it takes t = 18 s, therefore the average velocity is

Answer:
A total of 150 joules of work was done
Explanation:
Answer:
11.85 kg m/s
Explanation:
impulse = mass ( change in velocity )
= mass ( final velocity - initial velocity )
= 0.150 ( 32.0 - (-47.0))
= 0.150 ( 32.0 +47.0)
= 0.150 (79)
= 11.85 kg m/s
The intensity of a sound wave is defined as the amount of energy passing through a unit area of the wave front in unit of time.
Solution :
Acceleration due to gravity of the earth, g 

Acceleration due to gravity at 1000 km depths is :




= 8.23 m/s
Acceleration due to gravity at 2000 km depths is :




= 6.73 m/s
Acceleration due to gravity at 3000 km depths is :



= 5.18 m/s
Acceleration due to gravity at 4000 km depths is :




= 3.64 m/s