Answer:
bicycle A has a greater K.E.
Explanation:
K.E = 1/2mv²
bicycle A = 1/2 × 40 × 4² = 320J
bicycle B = 1/2 × 20 × 2² = 100J
bicycle A has a greater K.E. because it has bigger mass and moves with faster velocity
Rarefactions are where you see the wave further apart. Where it's closer together, it's called a compression.
Answer: 
Explanation:
The equation to calculate the center of mass 
of a particle system is:
In this case we can arrange for one dimension, assuming the geometric center of the Earth and the ladder are on a line, and assuming original center of mass located at the Earth's geometric center:
Where:
is the mass of the Earth
is the mass of 1 billion people
is the radius of the Earth
is the distance between the center of the Earth and the position of the people (2 m above the Earth's surface)
This is the displacement of Earth's center of mass from the original center.
Answer:
Let the weight of the ruler be X.
Now X acts in the middle, so we have 55-50 = 50cm
Since left hand movement= right hand movement
X(55-50)=90(95-55)
5X= 90×40
X=320cm
Hence the weight of the ruler is 320g
Explanation:
<span>a) 13 seconds
b) 130 m/s
The formula for the distance an object moves while under constant acceleration is d = 1/2AT^2. So let's define d as 830 m, A as 9.8m/s^2, and solve for T
830 m = 1/2 9.8 m/s^2 T^2
830 m = 4.9 m/s^2 T^2
Divide both sides by 4.9 m/s^2
169.3878 s^2 = T^2
Take the square root of both sides
13.01491 s = T
Since we only have 2 significant figures, round the result to 13 seconds which is the answer to the first part of the question. To find out how fast the marble is moving, just multiply T and A together
13 s * 9.8 m/s^2 = 127.4 m/s
Since we only have 2 significant figures, round the result to 130 m/s.</span>
