Question

=
so its initial velocity, ubi
Relative velocity of A W.r.t. B is VAB UA- UB = 0-u=-u
After some time t, the velocity of A will be va=u+at
VA = 0+gt
VA = gt
the velocity of B will be VB = u-gt
Now, Relative velocity of A w.r.t. B is VAB = VA-VB
= gt-u+gt = 2gt - u
Change in relative velocity of A w.r.t. B in time t is given by
(2gt-uh-u) = 2gt-u+u =2gt
... Their change in relative velocities will be 2gt
of to
A typical rain drop is about 4mm in diameter. If a rain drop falls from a cloud which is
at 1km above the ground, estimate its momentum when it hits the ground.
s: If the rain drop is supposed not attained terminal velocity, when it is falling from the cloud, then
the velocity with which it hits the ground can be calculated as follow:
Initial velocity (u)=0; acceleration (a)= g = 9.8ms-2
distance travelled (s) = 1km = 1000m;
Final velocity (v) = ?
v2 -u? = 2as = v= 2gh = +2x9.8x1000 = 140ms -1
4mm
rodius of rain drop, r=- = 2mm = 2x10-3,
m​

Answer 1

Answer:

सुप्रीम कोर्ट ने दिवाली और अन्य त्योहारों के अवसर पर पटाखे चलाने के लिए रात आठ बजे से 10 बजे (दो घंटे) की समय सीमा निर्धारित करते हुए देशभर में कम प्रदूषण उत्पन्न करने वाले ग्रीन पटाखे बनाने की अनुमति दे दी। कोर्ट ने कहा कि दिल्ली एनसीआर में सिर्फ ग्रीन पटाखे ही चलेंगे, इनके अलावा यहां अन्य पटाखों की बिक्री नहीं की जाएगी और लड़ी वाले पटाखे बिल्कुल नहीं बिकेंगे। इन आदेशों का पालन स्थानीय थाना प्रभारी करवाएंगे, जिसमें विफल रहने पर उनके खिलाफ कार्रवाई होगी।

जस्टिस एके सीकरी और जस्टिस अशोक भूषण की पीठ ने मंगलवार को दिए आदेश में ई-कॉमर्स वेबसाइटों को पटाखों की बिक्री करने से रोक दिया है। कोर्ट ने कहा कि इस आदेश का उल्लंघन करने पर उनके खिलाफ अवमानना की सख्त कार्रवाई की जाएगी।

$\huge\mathfrak\purple{™}$

Answer 2

Answer:

Hai,

Relative velocity of an object with respective to another object is the rate at which the object changes its position with respect to another object.

In simple words, relative velocity of an object 'U' w.r.t. another object 'V' is the velocity of object U as seen by the object V, when both the objects are in motion.

If 'x' be the angle between the direction of motion of the two objects U and V moving with velocities u and v respectively, then the relative velocity of object U w.r.t. V is square root of sum of square of u and square of v minus twice the product of u, v and cosine of x.

Again, if y be the angle made by relative velocity of object U w.r.t. V with U, then

tangent of y = v*sin(180-x)/{u+v*cos(180-x)}

= v*sin x/(u-v*cosx)

or, y = inverse of tangent of {v*sin x/(u-v*cosx)}

The above expression gives the direction of relative velocity of U w.r.t. V with U. That means, the object U seems to move in the durection making an angle y with U as seen by V. It can be used when the two objects move in any direction over and above parallel or antiparallel.

RULE TO DETERMINE RELATIVE VELOCITY

1. Take negative of the velocity of the object which is w.r.t., i.e., the object which is going to observe. In this case is V (i.e., -v).

2. Find the resultant of u and -v with angle (180-x) between them, by using either triangle law or parallelogram law of vectors addition.

The resultant will give the relative velocity of U w.r.t. V.

The magnitude of the resultant of the relative velocity of U w.r.t. V is equal to square root of sum of square of u, square of v and twice of the product of u, v and cosine of (180-x)

= square root of sum of square of u and square of v minus twice the product of u, v and cosine of x.

So, when both are moving along parallel straight line in same directiion,( angle x = 0 degree).

Relative velocity of U w.r.t. V = square root of sum of square of u, square of v and minus twice the product of u and v

= square root of square of (u-v) = u - v.

And, when both are moving along parallel straight line in opposite directiion,( angle x = 180 degree).

Relative velocity of U w.r.t. V = square root of sum of square of u, square of v and minus twice the product of u, v and cos(180) = square root of sum of square of u, square of v and plus twice the product of u, v and

= square root of square of (u+v) = u + v.

Explanation:

Hopefully u will satisfied with my answer of ur question ..!!