Answer:
So coefficient of kinetic friction will be equal to 0.4081
Explanation:
We have given mass of the block m = 0.5 kg
The spring is compressed by length x = 0.2 m
Spring constant of the sprig k = 100 N/m
Blocks moves a horizontal distance of s = 1 m
Work done in stretching the spring is equal to
This energy will be equal to kinetic energy of the block
And this kinetic energy must be equal to work done by the frictional force
So
So coefficient of kinetic friction will be equal to 0.4081
Answer:
3) 52500N
Explanation:
We use the mathematical definition of impulse as follows;
were F is the force experienced, t is the time of impact, m is the mass of the object and v is the velocity of impact.
Given; m = 4.5kg, v = 35m/s, t = 3 milliseconds
however,
From equation (1);
.
Substituting all necessary values into equation (2), we obtain the following;
Answer:
It's only 1.11 m/s2 weaker at 400 km above surface of Earth
Explanation:
Let Earth radius be 6371 km, or 6371000 m. At 400km above the Earth surface would be 6371 + 400 = 6771 km, or 6771000 m
We can use Newton's gravitational law to calculate difference in gravitational acceleration between point A (Earth surface) and point B (400km above Earth surface):
where G is the gravitational constant, M is the mass of Earth and r is the distance form the center of Earth to the object
So the gravitational acceleration at 400km above surface is only 0.885 the gravitational energy at the surface, or 0.885*9.81 = 8.7 m/s2, a difference of (9.81 - 8.7) = 1.11 m/s2.