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.
Density = 3/5 = 0.6g/cm^3. Since the density is less than the density of water, which is 1, the object will float.
Answer:
V₂ = 1.5 m/s
Explanation:
given,
speed of the first piece = 6 m/s
speed of the third piece = 3 m/s
speed of the second fragment = ?
mass ratios = 1 : 4 : 2
fragment break fly off = 120°
α = β = γ = 120°
sin α = sin β = sin γ = 0.866
using lammi's theorem

A,B and C is momentum of the fragments

4 x V₂ = 2 x 3
V₂ = 1.5 m/s
Well let's convert all these values out of standard form first:
2x10^-2 = 2x0.01 = 0.02m = 2cm
2x10^0m = 2x1 = 2m
2x10^-1m = 2x0.1 = 0.2m = 20cm
2x10^1m = 2x10 = 20m
Based on that, we know that 20cm is roughly equivalent to a basketball (at least it's closer than all the other values), so the answer is therefore 2 - 2x10^-1m