C. A mechanical wave generally travels faster in gases than liquids.
Answer:
(a) 8.362 rad/sec
(b) 6.815 m/sec
(c) 9.446 
(d) 396.22 revolution
Explanation:
We have given that diameter d = 1.63 m
So radius 
Angular speed N = 79.9 rev/min
(a) We know that angular speed in radian per sec

(b) We know that linear speed is given by

(c) We have given final angular velocity 
And 
Time t = 63 sec
Angular acceleration is given by 
(d) Change in angle is given by

Answer:
25.71 kgm/s
Explanation:
Let K₁ and K₂ be the initial and final kinetic energies of object A and v₁ and v₂ its initial and final speeds.
Given that K₂ = 0.7K₁
1/2mv₂² = 0.7(1/2mv₁²)
v₂ = √0.7v₁ = √0.7 × 20 m/s = ±16.73 m/s
Since A rebounds, its velocity = -16.73 m/s and its momentum change, p₂ = mΔv = m(v₂ - v₁) = 0.7 kg (-16.73 - 20) m/s = 0.7( -36.73) = -25.71 kgm/s.
Th magnitude of object A's momentum change is thus 25.71 kgm/s
Answer:
<h3>0.445</h3>
Explanation:
In friction, the coefficient of friction formula is expressed as;

Ff is the frictional force = Wsinθ
R is the reaction = Wcosθ
Substitute inti the equation;

Given
θ = 24°

Hence the coefficient of kinetic friction between the box and the ramp is 0.445