Hello!
Recall the equation for gravitational force:

Fg = Force of gravity (N)
G = Gravitational constant
m1, m2 = masses of objects (kg)
r = distance between the objects' center of masses (m)
There is a DIRECT relationship between mass and gravitational force.
We are given:

If we were to double one mass and triple another, according to the equation:

Thus:

Answer : 63 km/h
Explanation :
Outgoing distance = 300 km.
Outgoing speed = 93 km/h.
Break time = 1 h
Return distance = 300 km
Return speed = 56 km/h
Outgoing time = outgoing distance / outgoing speed
Outgoing time = 300 km / 93 km/h = 3.225806451612 h
Return time = return distance / return speed
Return time = 300 km / 56 km/h = 5.357142867142 h
Total distance =. Outgoing distance + return distance travelled
Total distance = 300 km + 300 km = 600 km
Total time = outgoing time + break time + return time
Total time = 3.225806451612 h + 1 h+ 5. 357142867142 h = 9.582949308754 h
Average speed = total distance / total time
Average speed = 600 km / 9.582949308754 h
Average speed = 62.61120462042 km/h = 63 km/h
I'm pretty sure it's D. negative acceleration
Complete Question
The complete question is shown on the first uploaded image
Answer:
The wavelength is 
Explanation:
From the question we are told that
The electric field is 
The magnetic field is 
From the above equation
and k is the wave number which is mathematically represented as

=> 
Where
is the wavelength