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Recall that:
Impulse = Change in Momentum = mass × change in velocity
Since both cars are identical and have the same initial velocity of 60 mph, them breaking to a stop means that they both experience the same change in velocity.
Thus, both of the cars' impulses are equal.
Explanation:
We have,
Semimajor axis is 
It is required to find the orbital period of a dwarf planet. Let T is time period. The relation between the time period and the semi major axis is given by Kepler's third law. Its mathematical form is given by :

G is universal gravitational constant
M is solar mass
Plugging all the values,

Since,

So, the orbital period of a dwarf planet is 138.52 years.
Explanation:
In local galactic group the force of expansion of universe is overcome by the force of attraction due to gravity. Best example is our own galaxy milky way and another giant galaxy in our local group Andromeda. Andromeda having enormous gravity is pulling milky way towards itself, overcoming the force of expansion.
So, there are possibilities of collision despite the expansion of universe at a rapid pace. It is estimated that the milky way and Andromeda will collide each other after about 50 billion years from now.
Acceleration is the rate of change of velocity as a function of time. For example a car traveling at 50 km/hr starts to accelerate, 10 seconds after, its speed changes to 100 km/hr then the acceleration of the car during the time can be calculated as below: initial speed = 50 km/hr.