Answer: d constint speed
Explanation: im 15 and no the answer
In the above case we can say that power given by external agent to pull the rod must be equal to the power dissipated in the form of heat due to magnetic induction.
Part a)
when we pull the rod with constant speed then power required will be product of force and velocity
here we will have

P = 4 W
v = 4 m/s
now we will have


So external force required will be 1 N
PART B)
now in order to find magnetic field strength we can say

here we know that induced EMF in the wire is E = vBL
so power due to induced magnetic field is given by


by solving above equation we will have

Answer: speed = 446.4m/s
Explanation: 1000mph implies that 1000 miles / 1 hour.
But it has been given that 1mile = 1609m,
hence
1000 miles = 1000 * 1609 = 1,609,000m
And I hour = 3600s
Hence 1000mph = 1,609,000/ 3600
1000 = 446.4m/s
A ladder 25 feet long is leaning against a house. The base of the ladder is pulled away at a rate of 2 ft/sec.
a.) How fast is the top of the ladder moving down the wall when the base of the ladder is 12 feet from the wall?
Answer:
dy/dt = -1.094ft/sec
Explanation:
Given that:
dz/dt = 0,
dx/dt = 2,
dy/dt = ?
Hence, we have the following
Using Pythagoras theorem
We have 25ft as the hypotenuse, y as the opposite or height of wall, and x as the base of the triangle
X² + y² = z²,
12² + y² = 25²,
y² = 25² - 12²
y = √481
Therefore, we have the following:
2x dx/dt + 2y dy/dt,
= 2z dz/dt,
= 12 (2) √481 dy/dt,
= √481 dy/dt = -24,
= dy/dt = -1.094ft/sec
Therefore, final answer is -1.094ft/sec
Answer:
The object fell from about 38.14 meters
Explanation:
We can use the formula for displacement under accelerated motion due to gravity to find the velocity of the object had 30 m before hitting the ground :

Now, knowing this velocity, we can find the time it took to fall from the initial position to 30 m before hitting the ground:

And now we can find what is the total distance covered in 1.5 s plus 1.29 seconds for this free falling object:
