Use Coupon: CART20 and get 20% off on all online Study Material

Total Price: Rs.

There are no items in this cart.
Continue Shopping
Deepak Sharma Grade: 11

7. A boy throws a table tennis ball of mass 20 g upwards with a velocity of u 0 = 10 m/s at an angle q 0 with

the vertical. The wind imparts a horizontal force of 0.08 N, so that the ball returns to the starting point.

Then, the angle q 0 must be such that, tan q 0 is

(A) 0.2 (B) 0.4 (C) 2.5 (D) 1.2

7 years ago

Answers : (2)

AKASH GOYAL AskiitiansExpert-IITD
419 Points

Dear Deepak

see the pic for the solution

All the best.




Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation.

Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively : Click here to download the toolbar..


7 years ago
vikas askiitian expert
510 Points

for verticle motion

 Uy = U0COS@   &   ay = -g

 applying  VY = UY + ayt

    Vy at topmost point is zero so

 t= uy/g

tim of flight (T)= 2t=2Uy/g .........1

for horizontal motion


 Sx = UxT + axT2

finally particle reaches to same point so displacement  is zero ..

 0 = UxT + axT2/2    .........2

putting value of T in eq 2

Uy/Ux = g/a  .........3

max = force =0.08

ax = 4m/s2

now , UY/UX = Uocos@/Uosin@


option c is correct




7 years ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies
  • Complete JEE Main/Advanced Course and Test Series
  • OFFERED PRICE: Rs. 15,900
  • View Details
  • Kinematics & Rotational Motion
  • OFFERED PRICE: Rs. 636
  • View Details

Ask Experts

Have any Question? Ask Experts

Post Question

Answer ‘n’ Earn
Attractive Gift
To Win!!! Click Here for details