(A) 
The energy stored by the system is given by
where
P is the power provided
t is the time elapsed
In this case, we have
P = 60 kW = 60,000 W is the power
t = 7 is the time
Therefore, the energy stored by the system is
(B) 4830 rad/s
The rotational energy of the wheel is given by
(1)
where
is the moment of inertia
is the angular velocity
The moment of inertia of the wheel is
where M is the mass and R the radius of the wheel.
We also know that the energy provided is
So we can rearrange eq.(1) to find the angular velocity:
(C) 
The centripetal acceleration of a point on the edge is given by
where
is the angular velocity
R = 0.12 m is the radius of the wheel
Substituting, we find
Kinetic energy of the horse and rider = 1/2 (mass) (speed)²
At 4.0 m/s : KE = 1/2 (55kg) (4 m/s)² = 440 joules
At 6.0 m/s : KE = 1/2 (55kg) (6 m/s)² = 990 joules
She increased the kinetic energy of herself and her vehicle by 550 joules,
so she must have put at least that much work into it.
<u>Explanation for the given picture:</u>
Initially, three principles of movement proposed by Sir Isaac Newton in 1686 "Principia Mathematica Philosophiae Naturalis". The third law says that every action (force) in nature has an equal but has opposite reaction.
In other words, when object A produces force on object B, then this object B also exerts the same but opposite forces on object A. Remember that forces get exerted on various objects. For example, if we put a wooden block in the floor, this block will create a force that should be equal to its mass, W = mg, which will work down.
The photo above clearly shows a person jumping off a tree on a wooden board, and therefore bouncing on the board because of the force exerted by the wooden board. Newton's third law is important if a person uses his power as weight (W = mg), and this in turn turns the person upside down! hence
Newtons 3rd law applies in above picture.
Answer:
q = 7.542 x 10⁻⁷ C = 754.2 nC
Explanation:
The Coulomb's Law gives the magnitude of the force of attraction or repulsion between two charges:
F = kq₁q₂/r²
where,
F = Force of attraction or repulsion = 0.2 N
k = Coulomb's Constant = 9 x 10⁹ N m²/C²
r = distance between charges = 16 cm = 0.16 m
q₁ = magnitude of 1st charge
q₂ = magnitude of 2nd charge
Since, both charges are said to be equal here.
q₁ = q₂ = q
Therefore,
0.2 N = (9 x 10⁹ N m²/C²)q²/(0.16 m)²
(0.2 N)(0.16 m)²/(9 x 10⁹ N m²/C²) = q²
q = √(5.88 x 10⁻¹³ C²)
<u>q = 7.542 x 10⁻⁷ C = 754.2 nC</u>
Answer:
Higher.
Explanation:
The greater the frequency the bigger the amplitude gets and the greater pitch gets.
Think - more energy, bigger waves, more waves, and higher sound
