(263.1 years) x (half-life / 87.7 years) = 3 half-lifes
In 3 half-lifes, (1/2 x 1/2 x 1/2) = 1/8 of the atoms in a sample remain unchanged.
That's 12.5% that remain unchanged.
The other 87.5% of the atoms in the sample have decayed, and changed to either other isotopes of plutonium or into atoms of other elements.
Answer:
V = 5.4 m/s
Explanation:
It is given that,
Let mass of the block, m = 10 kg
Spring constant of the spring, k = 2 kN/m = 2000 N/m
Speed of the block, v = 6 m/s
Compression in the spring, x = 15 cm = 0.15 m
Let V is the speed of the block moving at the instant the spring has been compressed 15 cm. It can be calculated using the conservation of energy of spring mass system.
![\dfrac{1}{2}m^2=\dfrac{1}{2}kx^2+\dfrac{1}{2}mV^2](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B2%7Dm%5E2%3D%5Cdfrac%7B1%7D%7B2%7Dkx%5E2%2B%5Cdfrac%7B1%7D%7B2%7DmV%5E2)
![mv^2=kx^2+mV^2](https://tex.z-dn.net/?f=mv%5E2%3Dkx%5E2%2BmV%5E2)
![V^2=\dfrac{mv^2-kx^2}{m}](https://tex.z-dn.net/?f=V%5E2%3D%5Cdfrac%7Bmv%5E2-kx%5E2%7D%7Bm%7D)
![V^2=\dfrac{10\times 6^2-2000\times (0.15)^2}{10}](https://tex.z-dn.net/?f=V%5E2%3D%5Cdfrac%7B10%5Ctimes%206%5E2-2000%5Ctimes%20%280.15%29%5E2%7D%7B10%7D)
V = 5.61 m/s
From the given options,
V = 5.4 m/s
Hence, this is the required solution.
Answer: part a) both the tension and gravity vectors will be pointing downwards.
part b) the tension vector will be pointing upwards and the gravity will be pointing downwards.
Explanation:
part a) Since you are looking at the FBD for the steel cable here, the tension will be pointing downwards because the girder is hung from the cable which creates a downwards tension. Gravity will always point downwards, to the ground.
part b) Since you are looking at the FBD for the girder here, the tension will be pulled upwards because the cable is weighted which creates an upwards tension. Gravity will always point downwards, to the ground.
Sorry for the poor explanation, but hopefully this makes sense.
Isn't a hypothesis making a theory? Based on that I guess the answer would be A. Making a theory, because you making the hypothesis is not part of testing it.
<span>It takes only one atom to make hydrogen; however, hydrogen is commonly found as H2, meaning two atoms make up hydrogen. Because of this, hydrogen is known as a diatomic element
The answer is prob A.1 but you didnt' give me a formula.</span>