Answer:
0.54454
104.00902 N
Explanation:
m = Mass of wheel = 100 kg
r = Radius = 0.52 m
t = Time taken = 6 seconds
= Final angular velocity
= Initial angular velocity
= Angular acceleration
Mass of inertia is given by

Angular acceleration is given by

Equation of rotational motion

The coefficient of friction is 0.54454
At r = 0.25 m

The force needed to stop the wheel is 104.00902 N
Answer:

Explanation:
From the exercise we have that

<em><u>To find how far from the edge of the piano does the cat strike the floor, we need to calculate its time first </u></em>

At the end of the motion y=0m

Solving for t
or 
Since the <u>time</u> can't be negative the answer is t=0.73
Knowing that we can calculate how far does the cat strike the floor

Answer:
831.4 J
Explanation:
Info given:
mass adult: 82.5kg
mass child: 14.7kg
height of wall: 1.25m
g = 9.81m/s^2
PE = mgh
For adult:
mgh = (82.5kg)(9.81m/s^2)(1.25m) = 1011.65 J
For child:
mgh = (14.7kg)(9.81m/s^2)(1.25m) = 180.25 J
Difference in PE: 1011.65 J - 180.25 J = 831.4 J
The momentum change =mass*velocity change. But sincevelocity change is not known another strategy must be used to find the momentum change. The strategy involves first finding the impulse (F*t = 1.0 N*s). Since impulse = momentum change, the answer is 1.0 N*s.
B. Gamma rays
Gamma rays have highest energy