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
The wrong type of lens-Microscope, concave
Explanation:
A microscope Basically uses t<u>wo convex lenses to magnify an object, or specimen.</u>
There are 2 lenses in a microscope
- <u>Object Lens:</u>The lens that is closer to the object
- <u>Eyepiece:</u>The lens that is closer to the eye
Both the object lens and the eyepiece, is a convex lens.
Answer:

Explanation:
From the question we are told that:
Mass 
Potential difference 
Magnitude 
Generally the equation for Velocity is mathematically given by




Generally the equation for Force is mathematically given by

Where


Therefore



The balloons will begin to shrink or deflate.
Answer:
The rotor's angular velocity is 82.73rad/s
Explanation:
It is a curvilinear movement of a constant radius. If there is uniform angular acceleration, then it is a circular motion with constant acceleration, whose equations are analogous to that of the translational motion.
Calculating the initial velocity of the rotor, V1 in rad/s
V1 = 610rev/minute × 6.28 × 1miute/60secs
V1 = 63.85rad/s
Using kinematic equation to calculate the final velocity of the rotor
Given:
Angular acceleration = 5.9rad/s^2
Time,t= 3.2seconds
V2 = V1 + a × t
V2 = 63.85 + (5.9)× (3.2)
V2 = 63.85 + 18.88
V2 = 82.73rads/s