Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 9 Answered

if a fan is placed on a small boat in opposite direction in which it should move moving, then why the boat does not move by the force of the fan
Asked by vibhav prasanna | 17 Sep, 2013, 08:44: AM
answered-by-expert Expert Answer

The crucial point here is internal versus external force.

The fan experiences a force in the direction opposite the flow of air (think of a propeller).

When the fan is on land, this force is not applied to the boat system. The flow of air from the fan produces a force on the sail which accelerates the boat.

If the fan is attached to the boat, the force on the fan is no longer external to the boat system. The fan acts as propeller applying a force to the boat opposite the flow of air. Ideally, it there is a sail capturing the full air flow produced by the fan, the force from the sail cancels the force from the fan. In reality, I imagine that the propulsion from the fan exceeds that from the sail so the boat moves opposite that desired.

Answered by | 19 Sep, 2013, 08:38: PM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 9 - Physics
boxes a and b each of mass 2 kg having dimension 20 cm to 10 cm into 8 cm and 40 cm into 30 cm and to 15 January respective at kept on a horizontal surface as shown the figure the ratio of pressure accepted by box a on the surface accepted by box be on the surface is take g 10 m per second
Asked by arushiarushi921 | 11 Oct, 2023, 08:45: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
write a Newton's 2law , derive an expression for F equals to Ma
question image
Asked by vomtimittagurupriya | 29 Sep, 2023, 05:52: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
solve this problem
question image
Asked by kunaljat51 | 24 Jul, 2022, 10:25: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
a bus accelerates at 2m per second for first 10 second after the start and retards at 1m per second for next 10 second find the total distance covered by the bus
Asked by komalpoonia636 | 16 Jun, 2022, 02:07: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Questions 23-25 are based on the information given below. Read the information and answer the questions that follow:A bob of mass ‘m’ is suspended by a string, g be the acceleration due to gravity the bob.When the bob is stationary, the tension ‘T’ in the string is T=mg.When the bob is pulled up with an acceleration ‘a’ the tension in the string is given by T= m (g + a)When the bob is allowed to move down with an acceleration ‘a’, the tension T in the string is given byT= m (g –a)  
Asked by avishisanghai | 20 Feb, 2022, 05:19: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
The weight of a boy on the surface of earth is 294N. Find its mass.
Asked by charvi | 26 Nov, 2021, 06:27: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A block of wood is kept on a horizontal table the mass of the wooden block is 6 kg and its dimensions are 10 into 10 into 10 what is the pressure exerted by the wooden block on the table
Asked by aanchishraddha | 16 Nov, 2021, 09:27: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A boy of mass 45 kg running 6 m/s jumps onto a 30 kg trolley moving in the same direction at 1.5 m/s. Their common velocity will be: A. 4.0 m/s B. 4.2 m/s C. 6.5 m/s D. 8.3 m/  
Asked by nishitatrambadia | 21 Oct, 2021, 09:38: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Unbalanced force can also change the shape,size of the body as Balanced force do
Asked by anuragyvidya | 28 Sep, 2021, 12:47: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is linear momentum ?
Asked by frusbJusyktsnis | 17 Sep, 2021, 12:03: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×