Zigya Logo

Chapter Chosen

Motion in Straight Line

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 police van moving on a highway with a speed of 30 km h-1 fires a bullet at a thief’s car speeding away in the same direction with a speed of 192 km h-1. If the muzzle speed of the bullet is 150 m s-1, with what speed does the bullet hit the thief’s car ? (Note: Obtain that speed which is relevant for damaging the thief’s car).

Given, 


Speed space of space the space police space van comma space straight v subscript straight p space end subscript equals space 30 space km divided by straight h space equals space 8.33 space straight m divided by straight s
Muzzle space speed space of space the space bullet comma space vb space equals space 150 space straight m divided by straight s space
Speed space of space the space thief ’ straight s space car comma space straight v subscript straight t space end subscript equals space 192 space km divided by straight h space equals space 53.33 space straight m divided by straight s

The space he space bullet space is space fired space from space straight a space moving space van comma
therefore space resultant space speed space can space be space obtained space as colon

150 space plus space 8.33 space equals space 158.33 space straight m divided by straight s

Both space the space vehicles space are space moving space in space the space same space direction. space

So comma space velocity space with space which space the space bullet space hits space the space
thief ’ straight s space car space is comma space

straight v subscript bt space equals space straight v subscript straight b space – space straight v subscript straight t

space space space space space equals space 158.33 space – space 53.33

space space space space space equals space 105 space straight m divided by straight s

192 Views

What is rest?

When an object does not change its position with time, with respect to it's surroundings. In such a case the object is said to be at rest. 
1215 Views

What is motion?

When an object changes it's position with time, with respect to it's surroundings, the object is said to be in motion. 
657 Views

What is the most essential thing to study the motion of a body?

The most essential thing to study the motion is reference frame. Rest and motion are relative terms. It means that an object in one situation can be in rest but in another situation, the same object will be in motion. 
650 Views

Is absolute rest or absolute motion possible?

Absolute rest and absolute motion is not possible because there is no point in the universe which is at rest and can be taken as point of reference. The planet Earth is in continuous motion. 
1986 Views

Can a body be always at rest in some frame?

Yes, a body is always at rest in a frame which is fixed with the body itself. 
746 Views

1.png
curious learner
Do a good deed today
Refer a friend to Zigya