Answer:
A. Ahmed has a greater tangential speed than Jacques.
D. Jacques and Ahmed have the same angular speed.
Explanation:
Kinematics of the merry-go-round
The tangential speed of the merry-go-round is calculated using the following formula:
v = ω*R
Where:
v is the tangential speed in meters/second (m/s)
ω is the angular speed in radians/second (rad/s)
R is the angular speed in meters (m)
Data
dA = RA : Ahmed distance to the axis of rotation
dJ = RJ : Jacques distance to the axis of rotation
Problem development
We apply the formula (1)
v = ω*R
vA= ω*RA : Ahmed tangential speed
vJ= ω*RJ : Jacques tangential speed
Ahmed is at a greater distance from the axis of rotation than Jacques, then,
RA ˃ RJ and Ahmed and Jacques have the same speed ω, then:
vA ˃ vJ
To solve this problem we must basically resort to the kinematic equations of movement. For which speed is defined as the distance traveled in a given time. Mathematically this can be expressed as

Where
d = Distance
t = time
For which clearing the time we will have the expression

Since we have two 'fluids' in which the sound travels at different speeds we will have that for the rock the time elapsed to feel the explosion will be:


In the case of the atmosphere -composite of air- the average speed of sound is 343m / s, therefore it will take


The total difference between the two times would be


Therefore 3.357s will pass between when they feel the explosion and when they hear it
Answer:
The work done by Joel is greater than the work done by Jerry.
Explanation:
Let suppose that forces are parallel or antiparallel to the direction of motion. Given that Joel and Jerry exert constant forces on the object, the definition of work can be simplified as:

Where:
- Work, measured in joules.
- Force exerted on the object, measured in newtons.
- Travelled distance by the object, measured in meters.
During the first 10 minutes, the net work exerted on the object is zero. That is:





In exchange, the net work in the next 5 minutes is the work done by Joel on the object:


Hence, the work done by Joel is greater than the work done by Jerry.
Answer:
B
Explanation:
because it change heat with the surrounding