1) Answer D not at all
The car is not experiencing any frictional force so that implies that there is no force acting on the car once it starts motion. So, according law of inertia, the car will continue to move and no other force is required.
Friction force is the resistance force that opposes the motion of any object. It arises due to the contact of surfaces.
2) Answer C none
There is no force on any spaceship moving far from any planet. So, according to law of inertia the spacecraft will continue to move at same speed.
Law of inertia states that any object keeps in the state of motion or rest unless a non zero external force is applied on it.
Force
Newton, abbreviated as N
Mu = 8.66 × 10^25 kg
Explanation:
centripetal force = gravitational force

where
m = mass of moon Ariel
mu = mass of Uranus
r = radius of Ariel's orbit
v = Ariel's velocity around Uranus
To find the velocity, we need to find the circumference of the no orbit and then divide it by the period (2.52 days):
circumference = 2πr = 2π×(1.91 × 10^8 m)
= 1.2 × 10^9 m
period = 2.52 days × (24 h/1 day)×(3600 s/1 hr)
= 2.18 × 10^5 s
v = (1.2 × 10^9 m)/(2.18 × 10^5 s)
= 5.5 × 10^3 m/s
(5.5 × 10^3 m/s)^2/(1.91 × 10^8 m) = (6.67 × 10^-11 m^3/kg-s^2)Mu/(1.91 × 10^8 m)^2
Solving Mu,
Mu = 8.66 × 10^25 kg
Answer:
Yes it would be a lunar eclipse here is an image that I found that might help but during a lunar eclipse when the moon is directly behind earth it will be a full moon
Explanation:
centripetal acceleration always points towards the center of the circular path and velocity of object in circular motion always points towards the tangent on the the circle in this way centripetal acceleration and velocity are perpendicular to each other and the dot product of perpendicular vectors is always zero,
therefore v•a=vacosα...........(1)
here α is angle between centripetal acceleration and velocity which is 90
therfore,
From equation (1)
v.a= vacos90
v.a=vax0..............(because cos90=0)
v.a=0 m^2
centripetal acceleration vector points towards center it means it point towards inwards direction, so it lies along the radius vector,and radius vector points towards outward direction of the circle in this way centripetal acceleration and radius vector are in exact opposite direction so angle between them is 180 degree,
therefore r x a = rasin180
rxa=rax0 (because sin180=0)
rxa=0m^2/s^2 .