Explanation :
It is given that, the driver accelerates from a stop sign, cruises for 20 s at a constant speed of 60 km/h, and then brakes to come to a stop 40 s after leaving the stop sign.
We know that acceleration is defined as the rate of change of velocity.
Where
dv is the change in velocity, dv = 0 - 60 m/s = -60 m/s
dt is the change in time, dt = 40 s - 30 s = 10 s
So, 
From the graph it is clear that, from 30 s to 40 s the car is decelerating. So, at every second within this time the value of acceleration will be same i.e. 
.
Sodium chloride, NaCl, is formed when a sodium atom transfers its electron to a chlorine atom. The difference in charge between the two atoms creates a(n) electrostatic attraction that bonds them together.
Antioxidant are compounds found in foods..they help to prevent damage of the cell
Answer:
Explanation:
Y = 5 Sin27( .2x-3t)
= 5 Sin(5.4x - 81 t )
Amplitude = 5 m
Angular frequency ω = 81
frequency = ω / 2π
= 81 / (2 x 3.14 )
=12.89
Wave length λ = 2π / k ,
k = 5.4
λ = 2π / 5.4
= 1.163 m
Phase velocity =ω / k
= 81 / 5.4
15 m / s.
The wave is travelling in + ve x - direction.
Answer: option B: conduction.
Conduction is the heat transfer that happens between two bodies in direct contact, due to the collision of the molecules, atoms and electrons within the body (microscopical level).
