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Grade 12th passMechanics

a motor car is going due north at a speed of 50km/h. it makes a 90 degree left turn without changing the speed. the change in the velocity of the car is about.

80km.h towards west

70kmk/h towards south – west

70km/h towards north west

zero

anurag ramteke

11 Years agoGrade 12th pass

5 Answers

stenly

11 Years ago

the magnitude remains constant while the direction changes.draw the resultant.the resultant will be along north west..so, the change in vel is 70kmph towards north-west.

Rahul

9 Years ago

Use vector concept.. The resultant will be obtained by us in northwest direction so by using triangle law of vector addition we get the ans 70km/hr in north west direction

Manisha

8 Years ago

The above process is correct but the direction should be south west.Using vector formula u can calculate the magnitude and by drawing diagram the direction.

Jitendra

8 Years ago

answer will be 70.7 km/h towards south-west

consider these velocities on an x-y plane with vectors i and j (+i = East, -i = West, +j = North, -j = South):

initial velocity = 50j.

final velocity = -50i.

change in velocity (Δv) = final velocity – initial velocity = -50i -50j

and -i direction (west) and -j direction (south), so the total change in velocity will be pointing towards the southwest.

|Δv| = √[(-50)² + (-50)²]
|Δv| = 70.7 km/h

Kushagra Madhukar

6 Years ago

Dear student,

Please find the attached solution to your problem below.

Consider these velocities on an x-y plane with vectors i and j (+i = East, -i = West, +j = North, -j = South):

initial velocity = 50j.

final velocity = -50i.

change in velocity (Δv) = final velocity – initial velocity = -50i -50j

and -i direction (west) and -j direction (south), so the total change in velocity will be pointing towards the southwest.

|Δv| = √[(-50)² + (-50)²]

|Δv| = 70.7 km/h

Hence, 70 km/h towards south – west will be the correct option.

Thanks and regards,

Kushagra

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