Answer: The bottom of the ladder is moving at 3.464ft/sec
Explanation:
The question defines a right angle triangle. Therefore using pythagorean
h^2 + l^2 = 10^2 = 100 ...eq1
dh/dt = -2ft/sec
dl/ dt = ?
Taking derivatives of time in eq 1 on both sides
2hdh/dt + 2ldl/dt = 0 ....eq2
Putting l = 5ft in eq2
h^ + 5^2 = 100
h^2 = 25 = 100
h Sqrt(75)
h = 8.66 ft
Put h = 8.66ft in eq2
2 × 8.66 × (-2) + 2 ×5 dl/dt
dl/dt = 17.32 / 5
dl/dt = 3.464ft/sec
Answer:
plz write your questions in English
Answer:
The force is 274 N.
Explanation:
In figure 2:
(d) Let the tension in the string is T.
According to the Newton's second law,
Net force = mass x acceleration
Apply for 200N.
Now put in (1)
T - 114.7 = 20.4 x 7.81
T = 274 N
The water. Take the specific heat of steel, estimate the volume of the nail, you know the volume of the water, which has a specific heat of one. Or be obvious. If you dropped a red hot nail into a liter of cold water, what would happen?
Answer:
Water
