Answer:
Explanation:
Total length of the wire is 29 m.
Let the length of one piece is d and of another piece is 29 - d.
Let d is used to make a square.
And 29 - d is used to make an equilateral triangle.
(a)
Area of square = d²
Area of equilateral triangle = √3(29 - d)²/4
Total area,

Differentiate both sides with respect to d.

For maxima and minima, dA/dt = 0
d = 8.76 m
Differentiate again we get the

(a) So, the area is maximum when the side of square is 29 m
(b) so, the area is minimum when the side of square is 8.76 m
Answer: 60m/s
Explanation:
The wavespeed is the distance covered by the wave in one second. It is measured in metre per second, and represented by the symbol V
Wavespeed (V) = Frequency F x wavelength λ
i.e V = F λ
In the first case:
Wavespeed = 30 m/s
Frequency of sound = 6Hz
Wavelength = 5m
In the second case:
Wavespeed = ?
Frequency of sound = (2x 6Hz = 12Hz)
Wavelength = 5m (remains constant)
Apply V = F λ
Wavespeed = 12 Hz x 5m
Wavespeed = 60m/s
Therefore, when frequency is doubled, the speed is also doubled. Thus, the new speed of the wave is 60m/s
Answer:
F = 36 kN
Explanation:
It is given that,
The pressure on the base of the fish tank is 4000N/m².
The base of the tank is a rectangle measuring 2.0m by 4.5m.
Area of the base of the tank is 9 m²
We need to find the force on the base caused by the base of the water. Pressure on the base of the tank is given by the force acting per unit area such that,

So, the force of 36 kN is acting on the base by the base of water.
Answer:
The total tension in the child's neck muscle, T = 56.51 N
Explanation:
Let m = mass of the child's neck
Radius of the curve, r = 2.40 m
The child's speed, v = 3.35 m/s
The tension force on the child's neck when he raises his head up off the floor, 
The tension force on the child's neck when he raises his head from the wall of the slide, 

Since he makes a circular turn in water, the radial acceleration can be given by the equation:


The total tension in the child's neck muscle till be calculated as:
