IT is important to get enough sleep every night so that your body can recharge, sort memories, heal and allow you to do the simple life tasks like staying awake and walking!
Answer:
2/3
Explanation:
It is important to bear in mind that momentum is generated by the fluid. Momentum is proportional to the mass and velocity, therefore increasing the mass(density) of the liquid by a factor of 2, while the velocity is constant, increases the momentum of fluid (and rocket) by 2. For any closed system, the momentum is conserved. With that in mind, the momentum of the fluid is equal to but opposite in direction to the momentum of the rocket. Velocity of the rocket given by v=p/m (Where p=momentum of the rocket initially and m is its initial mass). The mass of the rocket increases 3 times. So....
Initially:
vi=p/m
Now:
vf=2p/3m
<h3>The ratio is given by:</h3>
vf:vi = 2p/3m:p/m
Complete question
A student measures the mass of a 1.0 kg standard bar. He obtains measurements of 0.77 kg, 0.78 kg, and 0.79 kg. Which describes his measurements
a)precise but not accurate
b)accurate but not precise
c)neither precise nor accurate
d)both precise and accurate
Answer:
The measurement is precise but not accurate
Explanation:
A measurement can either be precise or accurate.
- A Precise measurement describes how close the measured values are to each other.
- An accurate measurement describes how close a measured value is to the true value.
In this question, the measured values (0.77 kg, 0.78 kg and 0.79 kg) are far from the true value (1.0 kg), therefore the measurement is not accurate.
However, the measured values (0.77 kg, 0.78 kg and 0.79 kg) are close to each other, therefore the measurement is precise.
Therefore the correct option is 'a' the measurement is precise but not accurate
Answer:
a) τ = 4.47746 * 10^25 N-m
b) E = 2.06301 * 10^13 J
c) P = 3.25511*10^21 W
Explanation:
Given:
- The radius of earth r = 6.3781×10^6 m
- The angular speed of earth w = 7.27*10^-5 rad/s
- The time taken to reach above speed t = 5 yrs = 1.57784760 * 10^8 s
- The mass of earth m = 5.972 × 10^24 kg
- The inertia of sphere I = 2/5 * m* r^2
Solution:
- The angular acceleration of the earth from rest to w is given by α:
α = w / t
α = (7.27*10^-5) / (1.57784760 * 10^8)
α = 4.60754*10^-13 rad/s^2
- The required torque τ is given by:
τ = I*α
τ = 2/5 * m* r^2 * α
τ = 2/5 *(5.972 × 10^24) * (6.3781×10^6)^2 * (4.60754*10^-13)
τ = 4.47746 * 10^25 N-m
- The power required P to turn the earth to the speed w is:
P = τ*w
P = (4.47746 * 10^25)*(7.27*10^-5)
P = 3.25511*10^21 W
- The energy E required is :
E = P / t
E = (3.25511*10^21) / (1.57784760 * 10^8)
E = 2.06301 * 10^13 J
Answer:
Each part of a two-dimensional vector is known as a component. The components of a vector depict the influence of that vector in a given direction. The components of a vector depict the influence of that vector in a given direction.
Explanation:
hope this helps
