Plugging in for the Earth's mass and for G, we have 11.2 km/s for the escape velocity for an object launched from the Earth's surface. This is about 25,000 miles per hour
Answer:
Explanation:
a) Energy stored in spring = 1/2 k x² = .5 x k 0.1²
500 = 5 x 10⁻³ k ,
k = (500/5) x 10³ = 10⁵ N/m
b )
k = 4.5 x 10¹ = 45 N/m
Stored energy = 1/2 k x² = .5 x 45 x 8² x 10⁻⁴ =1440 x 10⁻⁴ J
This energy gets dissipated by friction .
work done by friction = μ mg d
d is the distance traveled under friction
so 1440 x 10⁻⁴ = μ x 3 x 9.8 x 2
μ = 245 x 10⁻⁴ or 0.00245 which appears to be very small. .
Answer:
Acceleration will increase.
Explanation:
The relation between force, mass and acceleration according to the Newton's second law of motion is given as:
F = ma
We are given that the driving force on the truck remains constant, so F is constant here. We can rewrite the above equation as:
![a=\frac{F}{m}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7BF%7D%7Bm%7D)
Since, F is constant, the acceleration of the truck is inversely proportional to the mass.
There is a hole at the bottom of the truck through which the sand is being lost at a constant rate. Since, the sand is being lost, the overall mass of the truck is being reduced.
Since, the acceleration of the truck is inversely proportional to the mass, the reduced mass will result in an increased acceleration.
So, the acceleration of the truck will increase.
Answer:
R2 = 300 Ohms
Explanation:
Let the two resistors be R1 and R2 respectively.
RT is the total equivalent resistance.
Given the following data;
R1 = 100 Ohms
RT = 75 Ohms
To find R2;
Mathematically, the total equivalent resistance of resistors connected in parallel is given by the formula;
![RT = \frac {R1*R2}{R1 + R2}](https://tex.z-dn.net/?f=%20RT%20%3D%20%5Cfrac%20%7BR1%2AR2%7D%7BR1%20%2B%20R2%7D%20)
Substituting into the formula, we have;
![75 = \frac {100*R2}{100 + R2}](https://tex.z-dn.net/?f=%2075%20%3D%20%5Cfrac%20%7B100%2AR2%7D%7B100%20%2B%20R2%7D%20)
Cross-multiplying, we have;
75 * (100 + R2) = 100R2
7500 + 75R2 = 100R2
7500 = 100R2 - 75R2
7500 = 25R2
R2 = 7500/25
R2 = 300 Ohms
1st <span>the total </span>energy<span> of an </span>isolated system<span> is constant; energy can be transformed from one form to another, but can be neither created nor destroyed. ▲U=Q-W
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2nd the total </span>entropy<span> can never decrease over time for an </span>isolated system, that is, a system in which neither energy nor matter can enter nor leave.
DS (Greater than or equal to) 0