Answer:
b) 1. Iron, silicates, carbon
2. Water
3. Methane, Ammonia, Carbon Dioxide.
Explanation:
Protoplanetry disk is the disk of gases and clouds of dust that rotates around the newly made star. The temperature of the protoplanetry disk actually determines the type of the planet that is to be formed. Inner part of the protoplanetry disk is closer to the sun thats why it is the hottest and denser part and composed of the materials like Iron, silicates, carbon as they have high melting points. Then comes those materials that exist in the solid form at lower temperatures such as the volatile materials like water. Ater that the protoplanetry disk is made of highly volatile materials that exists in solid from only at low coldest temperatures. So the outer part of the protoplanetry disk is made up of the Methane, Ammonia and Carbon Dioxide.
Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
Answer:
0.83 m/s
Explanation:
FIrst of all, we have to find the time of flight, i.e. the time the baseball needs to reach the ground. This can be done by using the equation for the vertical motion:

where
h is the initial height
u = 0 is the initial vertical velocity
g = 9.8 m/s^2 is the acceleration of gravity
t is the time
Substituting h = 1.8 m and solving for t,

We know that the horizontal distance travelled by the ball is
d = 0.5 m
Therefore, we can find the horizontal velocity (which is constant during the whole motion):

Uh it’s D i’m pretty sure