<span>The right answer here would be option C - the side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole. This is due to the magnetic rule of opposites attracting.</span>
Answer:
it will take 
to reach its final rotating speed
Explanation:
Let initially the turntable is at rest
So its initial angular velocity will be 
Let the turn table is rotating with an angular acceleration 
According to first equation of motion
We know that 
, here 
So
So it will take to reach its final rotating speed
Let m = 65 kg, the mass of the boy and skateboard.
Let v = speed of the boy and skateboard.
The momentum is
P = mv = (65 kg)*(v m/s) = 275 (kg-m)/s²
v = 275/65 = 4.23 m/s
Answer: 4.23 m/s
Answer:
292796435 seconds ≈ 300 million seconds
Explanation:
First of all, the speed of the car is 121km/h = 33.6111 m/s
The radius of the planet is given to be 7380 km = 7380000 m
From the relationship between linear velocity and angular velocity i.e., v=rw, the angular velocity of the car will be w=v/r = 33.6111/7380000 = 0.000000455 rad/s = 4.55 x 10⁻⁶ rad/sec
If the angular velocity of the vehicle about the planet's center is 9.78 times as large as the angular velocity of the planet then we have
w(vehicle) = 9.78 x w(planet)
w(planet) = w(vehicle)/9.78 = 4.55 x 10⁻⁶ / 9.78 = 4.66 x 10⁻⁷ rad/sec
To find the period of the planet's rotation; we use the equation
w(planet) = 2π÷T
Where w(planet) is the angular velocity of the planet and T is the period
From the equation T = 2π÷w = 2×(22/7) ÷ 4.66 x 10⁻⁷ = 292796435 seconds
Therefore the period of the planet's motion is 292796435 seconds which is approximately 300, 000, 000 (300 million) seconds
The correct option is (A) <span>the first law of thermodynamics
Explanation:
The first law of thermodynamics takes the idea of law of conservation of energy and modify it for thermodynamics systems. It is the total internal energy of the systems equals to the amount of heat added "to" the system and the workdone "by" the system given as:
</span>ΔU = Q - W
<span>Q = heat added TO the system
W = work BY the system
</span>ΔU = Total internal energy
<span>
But the total internal energy is CONSERVED; it means that energy cannot be created or destroyed; it can only be transformed from one form to another. Hence the correct option is (A).</span>
