Answer:

Explanation:
As we know that the level of intensity is given as

here we know



now the sound is travelling in all possible directions so we have



now for level of sound we have


Answer:
Current- the flow of free charges, such as electrons and ions
Drift velocity- the average speed at which these charges move
Answer:
Acceleration
Explanation:
The advertisement is describing the acceleration of the car.
Acceleration is the rate of change of velocity per unit of time. It can be expressed mathematically as;
Acceleration =
v is the final velocity
u is the initial velocity
t is the time taken
Any quantity that specifies the rate of change of velocity of a body within a given time frame is describing its acceleration.
Its about momentum. Momentum (p)=mass(m)xvelocity(v)
So for the first ball P=4x8=32kgm/s
For the second the momentum is zero as it is still.
So overall momentum its 32kgm/s
Momentum has to be conserved
After the collision the momentum of the 4kg ball is 4x4.8=19.2kgm/s
As momentum is conserved 32-19.2=12.8kgm/s remaining
So rearrange for velocity so v=p/m=12.8/1=12.8m/s for the 1kg ball
Answer:
The magnitude of the force exerted on the ball by the racquet is 94.73 N.
Explanation:
The force exerted on the ball is the following:

Where:
m: is the mass of the ball = 59 g
a: is the acceleration
The acceleration of the ball can be found with the following kinematic equation:

Where:
d: is the distance = 0.36 m
: is the final speed = 34 m/s
: is the initial speed = 0 (it start from rest)
Hence, the acceleration is:

Finally, the force is:
Therefore, the magnitude of the force exerted on the ball by the racquet is 94.73 N.
I hope it helps you!