Answer:
gravity
Explanation:
as the earth rotates on an axis, it causes an effect known as centripetal acceleration with is an acceleration that pulls objects towards the center of the object. in planets, we call this Gravity
Answer:
is the rock's speed.
Explanation:
Momentum is defined as motion possessed by the moving body's mass. Mathematically it a product of mas and velocity of the body.

Given : Mass of rock = m = 1.45 kg
Velocity of the rock = v
Momentum of the rock = P =


is the rock's speed.
Answer: The person sitting in the middle of the train sees the back of the train enter ing the tunnel before the front end comes out.
Explanation:
The similarity is that they both are types of bonds in molecules.
Ionic bonds are between a metal and a nonmetal.
Covalent bonds are between two nonmetals.
<span>Every 10s 5 waves; t1 = 2s for each wave
When v = 1.5m/s, 3 waves in 10s t2 = 10 / 3s
Calculating the frequency in first case f1 = 5 / 10 = 0.5
Calculating the frequency in second case f2 = 3 / 10 = 0.3
Using the Doppler formula f = (1-v/c) f0
For the formula f = f2, v = velocity of boat= 1.5 m/s, f0 = f1, c is velocity of wave
0.3 = 0.5 x (1 - 1.5/c) => 1.5/c = 1 - 0.6 => 1.5/c = 0.4 => c = 1.5/0.4
Velocity of the wave = 3.75 m/s</span>