Atruck is going 30 m/s when the driver applies the brakes for 4.7 s so that the truck slows down to 20 m/s. a) what is the acceleration of the truck? b) how far does the truck go during the 4.7 s?

Answer :

(a) The acceleration of the truck is,

(b) The distance covered by the truck is, 117.8 m

Explanation :  

By the 1st equation of motion,

...........(1)

where,

v = final velocity = 20 m/s

u = initial velocity  = 30 m/s

t = time = 4.7 s

a = acceleration of the truck = ?

Now put all the given values in the above equation 1, we get:

The acceleration of the truck is,

By the 2nd equation of motion,

...........(2)

where,

s = distance covered by the truck = ?

u = initial velocity  = 30 m/s

t = time = 4.7 s

a = acceleration of the truck =

Now put all the given values in the above equation 2, we get:

By solving the term, we get:

The distance covered by the truck is, 117.8 m

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​

heat the gas and measure the pressure