Explanation:
It is given that,
A planet were discovered between the sun and Mercury, with a circular orbit of radius equal to 2/3 of the average orbit radius of Mercury.
Mass of the Sun, 
Radius of Mercury's orbit, 
Radius of discovered planet, 

Let T is the orbital period of such a planet. Using Kepler's third law of planetary motion as :




T = 4135214.625 s
or
T = 47.86 days
So, the orbital period of such a planet is 47.86 days. Hence, this is the required solution.
The relationship between the distance covered, initial and final speeds, and time can be expressed through the equation,
First equation,
2ad = Vf² - Vi²
Substituting the known values,
2(a)(0.230 km) = (70 km/h)² - (40 km/h)²
The value of a from the equation is 7173.92 km/h².
Second equation,
d = (Vi)(t) + 0.5at²
Substituting the known values,
0.230 km = (40 km/h)(t) + (0.5)(7173.92 km/h²)(t²)
The value of t from the equation is 4.1818 x 10^-3 hours which is also equal to 0.2509 minutes or 15 seconds.
Answer: 15 seconds
Answer:
100 newtons
Explanation:
Given,
Jamal pushing a large box by a force, F = 100 N
Work done on the large box is, W = 0
It is because the applied force is less than the force of the friction between the two surfaces.
Yet, there will be a force that is exerted by the large box on Jamal.
According to newton's third law of motion, every action has an equal and opposite reaction. The reaction force is in the direction opposite to the force of action. But, their magnitude remains the same.

Hence, If the action force is 100 N, then the reaction force should be in 100 N