Answer:
29274.93096 m/s




Explanation:
= Distance at perihelion = 
= Distance at aphelion = 
= Velocity at perihelion = 
= Velocity at aphelion
m = Mass of the Earth = 5.98 × 10²⁴ kg
M = Mass of Sun = 
Here, the angular momentum is conserved

Earth's orbital speed at aphelion is 29274.93096 m/s
Kinetic energy is given by

Kinetic energy at perihelion is 
Potential energy is given by

Potential energy at perihelion is 

Kinetic energy at aphelion is 
Potential energy is given by

Potential energy at aphelion is 
Answer:
200 km/hr
Explanation:
Since he goes 80km per hour, multiply this by 2.5 or two and a half hours.
80 x 2.5 = 200 km/hr.
To solve this problem we will use the kinematic formula for the final velocity.

The final speed is 0 at the moment the player stops.
The time until it stops is 1.3 s
The initial speed is 200 feet / s Note (check the speed units in the problem statement, 200ft / s is very much and 200ft / h is very small)
Then, we clear the formula.

Because the player is slowing down, the acceleration goes in the opposite direction to the player's movement, and that is why it is negative.
To answer part b) we use the following formula.

Yes, but there is only 1 atom like that and is is hydrogen. Hydrogen is the only element that could have a nucleus with one proton and no neutrons exist.