Answer:

Explanation:
Let m be the mass of a little car and m' be the mass of another car.
We know that,
Force = mass × acceleration
ATQ,
m × a = 2m × a'
a = 2 × a'

So, the acceleration of another little car is equal to
.
Answer:
45.93°
Explanation:
The angle of incidence is given as 32.7°
The refractive index of the water that is 
Refractive index of the air that is
(because the refractive index of air is 1 )
We have to find the angle at which the light leave the water means angle of refraction
So according to snell's law 


r =45.93°
So the light leave the water at an angle of 45.93°
Explanation:
speed of light= c
wave length= L
frequency= f
c=Lf → L= c/f → L= 3 × 10⁸/ 27 × 10⁹ → L = 1/90 ≈ 0.011 m
Accuracy describes how close a measurement is to the truest value while precision shows how close the measurements are to one another when repeated analysis of the same measurements are performed. Precision most likely is free from any any variation.
Answer:
The rock's final speed at the required altitude will be 42.24 m/s.
Explanation:
Let's start by finding the initial vertical speed.
Vertical Speed = 1.61 * Sin (53.2°)
Vertical Speed = 0.8 m/s
We want to know the speed of the rock when it is at an altitude of 91 km.
The total displacement of the rock from its starting position will thus be equal to -91 km
We can use this in the following equation:


t = 4.3918 seconds
Thus it takes 4.3918 seconds to reach the required altitude. We can now find the speed as follows:



Thus the rock's final speed at the required altitude will be 42.24 m/s.