Answer:
24.07415 rpm
Explanation:
= Coefficient of friction = 0.63
v = Velocity
d = Diameter = 4.9 m
r = Radius = 
m = Mass
g = Acceleration due to gravity = 9.81 m/s²
Here the frictional force balances the rider's weight

The centripetal force balances the weight of the person

Velocity is given by

Converting to rpm

The minimum angular speed for which the ride is safe is 24.07415 rpm
<span>22.5 newtons.
First, let's determine how much energy the stone had at the moment of impact. Kinetic energy is expressed as:
E = 0.5mv^2
where
E = Energy
m = mass
v = velocity
Substituting known values and solving gives:
E = 0.5 3.06 kg (7 m/s)^2
E = 1.53 kg 49 m^2/s^2
E = 74.97 kg*m^2/s^2
Now ignoring air resistance, how much energy should the rock have had?
We have a 3.06 kg moving over a distance of 10.0 m under a force of 9.8 m/s^2. So
3.06 kg * 10.0 m * 9.8 m/s^2 = 299.88 kg*m^2/s^2
So without air friction, we would have had 299.88 Joules of energy, but due to air friction we only have 74.97 Joules. The loss of energy is
299.88 J - 74.97 J = 224.91 J
So we can claim that 224.91 Joules of work was performed over a distance of 10 meters. So let's do the division.
224.91 J / 10 m
= 224.91 kg*m^2/s^2 / 10 m
= 22.491 kg*m/s^2
= 22.491 N
Rounding to 3 significant figures gives an average force of 22.5 newtons.</span>
<h2>The emf produced is 7.2 V</h2>
Explanation:
When coil is placed in the magnetic field , the flux attached with it can be found by the relation . Flux Ф = the dot product of magnetic field and area of coil .
Thus Ф = B A cosθ
here B is magnetic field strength and A is the area of coil .
The angle θ is the angle between coil and field direction .
When coil rotates , the angle varies . By which the flux varies . The emf is produced in coil due to variation of flux . The relation for this is
The emf produced ξ = -
= B A sinθ 
Now in the given problem
5 = 0.38 x A x
I
Now if the magnetic field is 0.55 T and all the other terms are same , the emf produced
ξ = 0.55 x A x
Ii
dividing II by I , we have
=
= 1.45
or ξ = 7.2 V
Force of friction=75 N
Explanation:
we use Newton's second law of motion
F- Ff= ma
F = applied force=250 N
Ff= force of friction
a= acceleration= 5.83 m/s²
m= mass=30 kg
250- Ff= 30 (5.83)
Ff=250-30(5.83)
Ff=250-175
Ff=75 N
Refer to the diagram shown below.
h = original height of the pelican when the fish is dropped (not relevant).
S = distance traveled by the fish as a function of time, measured upward.
u = 0.5 m/s, the upward velocity with which the fish is dropped.
g = 9.8 m/s², the acceleration due to gravity.
Use the following equation:
S = ut + (1/2)gt²
S = (0.5 m/s)*(2.5 s) + 0.5*(-9.8 m/s²)*(2.5 s)²
= -29.375 m
The negative sign means that the fish drops by 29.375 m from the original height of h.
Answer: The fish is 29.375 m below where the pelican dropped it after 2.5 s.