Answer:
v = 8.8 m /s
Explanation:
For listener and source going away from each other the formula of Doppler effect is as follows

V is velocity of sound , v is velocity of listner and source of sound
f₀ is apparent frequency and f is real frequency
V = 343 , v = ? ,f = 210 , f₀ = 221
Put these value in the relation above
[/tex]
v = 8.8 m /s
(a) The free body of all the forces include, frictional force, weight of the box acting perpendicular and another acting parallel to the plane.
(b) When the box is sliding down, the frictional force acts towards the right.
(c) When the box slides up, the direction of the frictional force changes, it acts towards the left.
<h3>
Free body diagram</h3>
The free body diagram of all the forces on the box is obtained by noting the upward force and downward forces on the box as shown below;
/ W2
Ф → Ff
↓W1
where;
- Ff is the frictional force resisting the down motion of the box
- W1 is the perpendicular component of the box weight = Wcos(33)
- W2 is the parallel component of the box weight = Wsin(33)
(b) When the box is sliding down, the frictional force acts towards the right.
(c) When the box slides up, the direction of the frictional force changes, it acts towards the left.
Learn more about free body diagram of inclined objects here: brainly.com/question/4176810
The tension in the string B) It quadruples.
Explanation:
The ball is in uniform circular motion in a horizontal circle, so the tension in the string is providing the centripetal force that keeps the ball in circular motion. So we can write:

where:
T is the tension in the string
m is the mass of the ball
v is the speed of the ball
r is the radius of the circle (the lenght of the string)
In this problem, we are told that the speed of the ball is doubled, so
v' = 2v
Substituting into the previous equation, we find the new tension in the string:

Therefore, the tension in the string will quadruple.
Learn more about circular motion:
brainly.com/question/2562955
brainly.com/question/6372960
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Use the first kinematic formula
Vf = Vi + at
10 = 0 + 1(t)
10 = t
10 seconds
it depends upon what state they are in like in motion or res