+91-87964 74404
FlagBACK
Question icon
Grade 9Wave Motion

If a car travels first 40km at speed of 20km/h and next 80km at a speed of 40km/h. what is the
average speed of car during journey?

Profile image of ishan singh
5 Years agoGrade 9
Answers icon

1 Answer

Profile image of Ruz
5 Years ago
By definition, the average speed is given by-
 
\frac{total distance travelled}{total time taken}
 
We already know the total distance travelled, which is: 40km+ 80km= 120km
 
For calculating time, we use the equation s=v*t or t=s/v 
that is, time taken= distance/speed
 
For first part, time taken, t1= 40/20= 2 hours
For second part, time taken, t2= 80/40= 2 hours
 
So total time= 4 hours 
 
Putting this is our formula, avg speed= total distance/total time
We get, avg speed= 120/4= 30 km/h
 
 

Other Related Questions on wave motion

question mark
A particle on a speing executes shm when the particle is found at x=xmax/2 the speed of the partcle is 
A)vx=vmax 
B)vx=√3vmax/2
C)vx=√2vmax/2
D)vx=vmax/2
wave motion
1 Answer Available

Last Activity: 4 Years ago

question mark
displacement associated with three dimensional wave is given by sai x y is equal to 1 + 1 by 2 x + root 3 by 2 k x minus omega t show that the wave propagates along a direction making an angle 60 degree with the x-axis
wave motion
1 Answer Available

Last Activity: 4 Years ago

question mark
What do you mean by Energy of Simple Hormonic Motion?
 
wave motion
1 Answer Available

Last Activity: 4 Years ago

question mark
What is mean by motion and time define it's all types with there parts and their s.i. units.
wave motion
1 Answer Available

Last Activity: 4 Years ago

question mark
explain the effects of doppler effect in satellite communication
wave motion
1 Answer Available

Last Activity: 4 Years ago