The average speed of the car is 93.33 km/hr and the average velocity of the car is 40 km/hr.
The total distance cover in east direction is=100*3=300 km
The total distance cover in the west direction=80*1.5=120 km
The total distance covered is =300+120=420 km
And Total displacement of the car is =300-120=180 km
As we know that the average speed is given as
Avg Speed =Total Distance / Total time
=420/4.5=93.33 km/hr
As we know that the average velocity is given as
Avg Speed =Total Displacement/ Total time
=180/4.5=40 km/hr
Therefore, The average speed of the car is 93.33 km/hr and the average velocity of the car is 40 km/hr.
If you stand up in a big room and echo, your voice will echo
from the walls. As long as the room is empty. Since
the speed of sound is constant, depending on air density, the more humid the
air the faster and farther sound travels. The
speed of sound is constant, you could measure the time it takes for your voice
to echo off the walls. The same thing happens with Doppler radar, but it’s not voice,
it has higher frequency signals.<span> </span>
Answer:
I believe the answer is A and D.
I am unsure of C.
Answer:
Why do metals conduct heat so well? The electrons in metal are delocalised electrons and are free moving electrons so when they gain energy (heat) they vibrate more quickly and can move around, this means that they can pass on the energy more quickly.