The equation is the Law of Universal Gravitation. The gravitational constant G is equal to 6.67×10⁻¹¹ Nm²/kg². The mass of the Earth is <span>5.972 ×10</span>²⁴ kg. Compared to the mass of the Earth, the mass of the rocket is negligible. So, we don't need to know the mass of the rocket. Substituting the values:
F = (6.67×10⁻¹¹ Nm²/kg²)(5.972 ×10²⁴ kg)/(4000 miles*(1.609 km/1mile))²
F = 9616423.08 N
The work is equal to
W = Fd
W = (9616423.08 N)(2000 miles*1.609 km/mile)
W = 9.095×10¹⁰ Joules
The kinetic energy of an object is given by:
where m is the mass of the object and v its speed. The ball in this problem has a mass of m=0.2 kg and a kinetic energy of K=40 J, so we can rearrange the previous equation to find its speed:
I believe the answer is the core.
Answer:
The car that went 54 km in 2/3h was faster, 5/4 times faster than the other car
Explanation:
Average speed of a car is the ratio between the displacement 
and the time (t) it takes to do that displacement:
So, for the first car:
(1)
for the second car we have:
(2)
So, the second cart is faster than the first one. To find how many times divide speed 2 by speed 1:
The thermal efficiency of a combustion system is simply
the ratio of heat out and heat in, that is:
efficiency = heat out / heat in
efficiency = 1030 J / 1540 J
efficiency = 0.669
<span>So the efficiency is 0.669</span>
