Answer:
Height of wall is 12 ft.
Explanation:
In the shown figure, AB denotes the height of the wall, BC denotes the distance between foot of the ladder and wall and AC denotes the length of the ladder.
Let h be the height of wall. By Pythagoras Theorem,
(AB)² + (BC)² = (AC)²
According to the problem, AC = 13 ft, AB = h ft and BC = (h - 7) ft:
h² + (h-7)² = (13)²
h² + h² + 49 - 14h = 169
2h² - 14h - 120 = 0
h² - 7h - 60 = 0
By mid-term splitting,
h² - 12h + 5h - 120 = 0
h(h - 12) + 5(h - 12) = 0
(h - 12) x (h + 5) = 0
h = 12 ft or h = -5 ft
Since, height of wall cannot be negative. Hence, the height of wall is 12 ft.
It is fairly easy to build an electromagnet. All you need to do is wrap some insulated copper wire around an iron core. If you attach a battery to the wire, an electric current will begin to flow and the iron core will become magnetized. When the battery is disconnected, the iron core will lose its magnetism. Follow these steps.
Step 1 - Gather the Materials
One iron nail fifteen centimeters (6 in) long
Three meters (10 ft) of 22 gauge insulated, stranded copper wire
One or more D-cell batteries
Step 2 - Remove some Insulation
Step 3 - Wrap the Wire Around the Nail
Step 4 - Connect the Battery
Answer:
Final speed of boat + man is 1.66 m/s
Explanation:
As we know that there is no friction on the system or there is no external force on this system
So here we can use momentum conservation here
so we have
m = 85 kg
M = 135 kg
v = 4.30 m/s
now we have
To solve this problem we will apply the principle of conservation of energy. For this purpose, potential energy is equivalent to kinetic energy, and this clearly depends on the position of the body. In turn, we also note that the height traveled is twice that of the rigid rod, therefore applying these concepts we will have
Therefore the minimum speed at the bottom is required to make the ball go over the top of the circle is 4.67m/s