Answer:
0.853 m/s
Explanation:
Total energy stored in the spring = Total kinetic energy of the masses.
1/2ke² = 1/2m'v².................... Equation 1
Where k = spring constant of the spring, e = extension, m' = total mass, v = speed of the masses.
make v the subject of the equation,
v = e[√(k/m')].................... Equation 2
Given: e = 39 cm = 0.39 m, m' = 0.4+0.4 = 0.8 kg, k = 1.75 N/cm = 175 N/m.
Substitute into equation 2
v = 0.39[√(1.75/0.8)
v = 0.39[2.1875]
v = 0.853 m/s
Hence the speed of each mass = 0.853 m/s
Answer: D. the distance between the highest points of consecutive waves
Explanation:
The wavelength of a wave is defined as the <em>distance traveled by a periodic perturbation that propagates through a medium in a given time interval</em>. It is usually represented by 
and can be calculated if the frequency of the wave is known, since there is an inverse relationship between both.
In the specific case of a periodic sine wave (which is the way in which a wave is usually represented graphically) the wavelength can be determined as the distance between two consecutive maxima of the disturbance.
Therefore, the correct option is D.
The 'plum pudding<span>' </span>model of the atom<span> was proposed by JJ Thomson, who had also discovered the </span>electron<span>. It was put forth before the discovery of the nucleus. According to this </span>model<span>, the </span>atom<span> is a sphere of positive charge, and negatively charged </span>electrons<span> are embedded in it to balance the total positive charge.</span>
Answer:
3.9 × 10^7 J
Explanation:
Given that a tank is is half full of oil that has a density of 900 kg/m3. Find the work W required to pump the oil out of the spout. (Use 9.8 m/s2 for g. Assume r = 15 m and h = 5 m.) W = 1.59 J
Solution
Since the tank is half full, the height = 2.5m
Pressure = density × gravity × height
Pressure = 900 × 9.8 × 2.5
Pressure = 22050 Pascal
The cross sectional area of the pump will be area of a circle.
A = πr^2
A = π × 15^2
A = 706.858 m^2
Using the formula
Density = mass/volume
Mass = density × volume
Mass = 900 × 706.86 × 2.5
Mass = 1590.435
Energy = mgh
Energy = 1590.435 × 9.8 × 2.5
Energy = 38965657.8 J
Since the work done = energy
Therefore, the work done = 3.9 × 10^7 J
