21. light changes its direction when travelling through a new medium because denser mediums have a higher angle of refraction.
Memorize this and you'll be able to do ALL of these: <em>1 kg = 1,000 g</em>
So if you have some grams, divide the number by 1,000 to get kilograms.
1,000 g = 1.000 kg
500 g = 0.500 kg
100 g = 0.100 kg
50 g = 0.050 kg
20 g = 0.020 kg
10 g = 0.010 kg
Answer:
velocity at the top: 0 m/s
acceleration at the top: -9.8 m/s²
Explanation:
Assuming up is positive and down is negative;
The velocity of the ball at the top of its path will be 0 m/s and the acceleration will be negative.
The velocity is 0 m/s because the ball does not move at the top of its path, and it switches from a positive velocity to a negative velocity. It must go through 0 in order to go from positive to negative.
The acceleration, however, is always negative no matter where the ball is in its motion. This negative acceleration causes the ball to slow down as it reaches the top, and speed up as it reaches the bottom.
<u>Think about it:</u> If there wasn't a negative acceleration, and it was instead 0, the ball would never come back down and instead keep going in a straight line.
Explanation:
We'll need two equations.
v² = v₀² + 2a(x - x₀)
where v is the final velocity, v₀ is the initial velocity, a is the acceleration, x is the final position, and x₀ is the initial position.
x = x₀ + ½ (v + v₀)t
where t is time.
Given:
v = 47.5 m/s
v₀ = 34.3 m/s
x - x₀ = 40100 m
Find: a and t
(47.5)² = (34.3)² + 2a(40100)
a = 0.0135 m/s²
40100 = ½ (47.5 + 34.3)t
t = 980 s
<span>Kinetic energy because it is taking the students to school.</span>
