Answer:
Option A
Explanation:
Mechanical waves requires some medium to travel through. They travel faster in the dense medium as compared to a free medium.
The speed of a mechanical wave is fastest in the solid medium and the slowest in the gaseous medium. Hence, as the wave traverses from gaseous medium to the solid medium, its speed increases.
Thus, option A is correct
Answer:
4.6834625323 m/s
0 m/s
Explanation:
s = Displacement
t = Time
Velocity is given by

The bird's average velocity for the return flight is 4.6834625323 m/s
In the whole episode the bird went 5220 km away from its nest and came back. This means the displacement is zero.
Hence, the average velocity for the whole episode is 0 m/s
Answer:
1.68 s
Explanation:
From newton's equation of motion,
a = (v-u)/t.................................. Equation 1
Making t the subject of the equation
t =(v-u)g............................. Equation 2
Where t = time taken for the bowling pin to reach the maximum height, v = final velocity bowling pin, u = initial velocity of the bowling pin, g = acceleration due to gravity.
Note: Taking upward to be negative and down ward to be positive,
Given: v = 0 m/s ( at the maximum height), u = 8.20 m/s, g = -9.8 m/s²
t = (0-8.20)/-9.8
t = -8.20/-9.8
t = 0.84 s.
But,
T = 2t
Where T = time taken for the bowling pin to return to the juggler's hand.
T = 2(0.84)
T = 1.68 s.
T = 1.68 s
IT IS EASIER TO CLIMB A SLANTED SLOPE
Answer: 
Explanation:
A direct proportionality means a linear relationship between two variables and rate of change means an application of derivatives. Hence, the mathematical model is:
