Chapter Chosen

Motion in A Plane

Book Chosen

Physics Part I

Subject Chosen

Physics

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12

A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 ms-1 to 20 ms-1 while passing through a distance 135 m in t second.  The value of t is 

  • 10

  • 1.8

  • 12

  • 9


D.

9

The problem requires kinematics equations of motion

Let u and v be the first and final velocities of particle an a and s be the constant acceleration and distance covered by it. 

From third equation of motion

v2 = u2 + 2as
(20)2 = (10)2 + 2a x 135
or
a = 300/2 x135 = 10/9 ms-2

Now using first equation of motion,


v= u +at

or 

straight t space equals space fraction numerator straight v minus straight u over denominator straight a end fraction space equals space fraction numerator 20 minus 10 over denominator left parenthesis 10 divided by 9 right parenthesis end fraction space equals space fraction numerator 10 space straight x 9 over denominator 10 end fraction space equals space 9 straight s

The problem requires kinematics equations of motion

Let u and v be the first and final velocities of particle an a and s be the constant acceleration and distance covered by it. 

From third equation of motion

v2 = u2 + 2as
(20)2 = (10)2 + 2a x 135
or
a = 300/2 x135 = 10/9 ms-2

Now using first equation of motion,


v= u +at

or 

straight t space equals space fraction numerator straight v minus straight u over denominator straight a end fraction space equals space fraction numerator 20 minus 10 over denominator left parenthesis 10 divided by 9 right parenthesis end fraction space equals space fraction numerator 10 space straight x 9 over denominator 10 end fraction space equals space 9 straight s
320 Views

Give three examples of vector quantities.

Force, impulse and momentum.
865 Views

What is a scalar quantity?

A physical quantity that requires only magnitude for its complete specification is called a scalar quantity.
1212 Views

Give three examples of scalar quantities.

Mass, temperature and energy
769 Views

What are the basic characteristics that a quantity must possess so that it may be a vector quantity?

A quantity must possess the direction and must follow the vector axioms. Any quantity that follows the vector axioms are classified as vectors. 


814 Views

What is a vector quantity?

A physical quantity that requires direction along with magnitude, for its complete specification is called a vector quantity.
835 Views