+91-705-589-3577
FlagBACK
Flag 10 grade science> A car covers its outward journey at 40kmp...
question mark

A car covers its outward journey at 40kmph. It is towed back, over exactly the same distance at 10mph. What is the average speed over the entire journey?
A)12mph B)14mph C)15mph D)20mph

SUDHARSANA V V , 8 Years ago
Grade 10
anser 3 Answers
Arun
Dear student
 
we can apply the formula 2xy/(x+y) for average speed.
Hence
 
Avg speed = 2*40*10/(40+10) = 800/50 = 16 kmph
 
Regards
Arun (askIITians forum expert)
Last Activity: 8 Years ago
SUDHARSANA V V
Before working out Km is to be converted in to miles isn`t it. Hence 40km isto be converted and then average speed to be found out.
Last Activity: 8 Years ago
Arun
Sorry, thanks for pointing it out.
 
40 kmph = 40/1.6 mph = 24.85 mph
 
Now avg speed = 2*24.85*10/34.85 = 14.26 mph
 
Hence option B is correct
Last Activity: 8 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Other Related Questions on 10 grade science

question mark

What type of questions asked from the lesson of magnetic effect of electric current 


10 grade science
1 Answer Available

Last Activity: 6 Months ago

question mark

Wavelength of green light is

A) 400-450 nm

B) 500-550 nm

C) 660-720 nm

D) 720-800 nm

10 grade science
1 Answer Available

Last Activity: 8 Months ago

question mark

What is the difference between anaerobic & aerobic respiration? Name some organism that uses the aerobic mode of respiration?

10 grade science
1 Answer Available

Last Activity: 8 Months ago

question mark

What are the main components of our environment? Explain each of them briefly.

10 grade science
1 Answer Available

Last Activity: 8 Months ago

question mark

What are examples of hydrotropism plants?

10 grade science
1 Answer Available

Last Activity: 8 Months ago