All that business about the crane and the rope and the falling
is only there to confuse us.
The piano ended up 5 meters above the ground.
Potential energy = (mass) (gravity) (height)
= (200 kg) (9.81 m/s²) (5 m)
= (200 · 9.81 · 5) (kg-m²/s²)
= 9,810 joules .
Answer:
The slower the train is moving, the less are the changes of the magnetic flux, thus the eddy currents become weaker.
Explanation:
A magnetic brakes is not a very efficient way of braking when a train is moving slowly because at low speeds, the changes in the magnetic flux are very less and so it causes the eddy current to become weaker.
Let us find the drag force which is proportional to the velocity of two conducting plates.
The EMF that is induced in the eddy currents are : 
The force which is due to the induced magnetic field is, 
Therefore, 

Here, force is directly proportional to the velocity of the two conducting plates.
Therefore, we can say that when the speed of the train is low, the magnetic flux changes are less and thus the eddy currents are weaker.
according to newton's third law, every action has equal and opposite reaction. in this scenario of making a jump from the boat onto a dock, as i jump my feet in contact with the boat push the boat in backward direction. hence the action force is the push by my feet on the boat. the boat reacts by applying a reaction force on my feet pushing the feet in forward direction. hence reaction force here is the force by the boat on the feet. due to the reaction force of the boat on feet, i am pushed in forward direction to reach the the dock.
Answer: 3.3 x 10^-28 J
Explanation: just answered on a quiz!! :)
Answer:
Explanation:
we can look for the final velocity of the object using the eqaution of motion as shown:
v² = u²+2gH
v is the final velocity
u is the initial velocity = 10m/s
g is the acceleration due to gravity = 9.81m/s²
H is the height of the object = 175m
Subxtitute the given parameters inti the formula and get v:
v² = 10²+2(9.81)(175)
v² = 100+3433.5
v² = 3533.5
v = √3533.5
v = 59.44m/s
Hence the final velocity of the object is 59.44m/s