Answer:
2.1 s
Explanation:
The motion of the ball is a projectile motion. We know that the horizontal range of the ball is

And that the initial speed of the ball is

at an angle of

So, the horizontal speed of the ball (which is constant during the entire motion) is

And since the horizontal range is 50 m, the time taken for the ball to cover this distance was

which is the time the ball spent in air.
Answer:
Orbital period, T = 1.00074 years
Explanation:
It is given that,
Orbital radius of a solar system planet, 
The orbital period of the planet can be calculated using third law of Kepler's. It is as follows :

M is the mass of the sun

T = 31559467.6761 s
T = 1.00074 years
So, a solar-system planet that has an orbital radius of 4 AU would have an orbital period of about 1.00074 years.
Answer:
C
Explanation:
Because everything on Earth falls at the same speed, the masses of the balls do not matter. Since the acceleration due to gravity is constant, their speeds will both be increasing at the same rate, and therefore the difference in speeds would remain constant until they hit the ground. Hope this helps!
Answer:
6.67×10⁻⁸ cm³/g/s²
Explanation:
6.67×10⁻¹¹ Nm²/kg²
= 6.67×10⁻¹¹ (kg m/s²) m²/kg²
= 6.67×10⁻¹¹ m³/kg/s²
= 6.67×10⁻¹¹ m³/kg/s² × (100 cm/m)³ × (1 kg / 1000 g)
= 6.67×10⁻⁸ cm³/g/s²
Outer planets are farther away and made up of gases. Inner planets closer. It's pretty much self explanatory. Hope this helps.