Question

The maximum resultant of two concurrent forces is 10N and their minimum resultant is 4N.The magnitude of large force is

Answer 1

Your answer is ----

when angle between two force is 0°,
Then resultant of both force is maximum

°•° resultant of two concurrent force is 10N

Let , the two forces be F1 and F2

•°• √F1^2+F2^2+2F1F2cos0° = 10

=> √F1+F2+2F1F2 = 10. [°•° cos0°=1]

=> √(F1+F2)^2 = 10

=> F1 + F2 = 10N .....(1)

Now,

When angle between two forces is 180°,
then resultant of both forces is minimum

°•° minimum resultant of both forces is 4N

•°• √F1+F2+2F1F2cos180° = 4N

=> √F1+F2-2F1F2 = 4N [°•° cos180°= -1]

=> √(F1-F2)^2 = 4N

=> F1 - F2 = 4N ......(2)


2F1 = 14N

=> F1 = (14/2)N

=> F1 = 7N

put this value in equation (1) , we get

F1 + F2 = 10N

=> 7N + F2 = 10N

=> F2 = 10-7

=> F2 = 3N


Hence , magnitude of largest force is 7N




adding equation (1)&(2) , we get

Answer 2

your answer is ----

firstly we state relation between kinetic energy and momentum

K.E = 1/2 mv^2

where ,

K.E = kinetic energy

m = mass

v = velocity

multiply both side by mass m , we get

K.E × m = 1/2 (mv)^2

=> 2m K.E = (mv)^2

°•° mv = momentum = p

=> p = √(2mK.E)