Answer:
My answer is 7.2 km
Explanation:
When Stephen goes to the south and then to the east, he is drawing a right triangle, where the 4 km and 6 km sides are the cathetus of a right triangle.
Then we use the Pithagorean theorem to solve this problem. We need to find the hypotenuse.
c² = a² + b²
c² = 4² + 6²
c² = 16 + 36
c² = 52
c = 7.2 km
Answer: (b)0.000012/k
Explanation:
The linear expansion of the metal rod is given by

where
is the linear expansion
is the initial length of the rod
is the linear expansivity
is the increase in temperature
By re-arranging the equation, we find the linear expansivity:

The rays of light coming from the Sun are parallel to each other, so when they are reflected by the concave piece of glass (which acts as a concave mirror) they converge into the focus of the mirror, which is

The radius of curvature of a concave mirror is twice its focal length, so in this case it is:
We are given –
- Mass of boiling ball is, m = 4 kg
- Speed is, v = 3 m/s
- Momentum, P =?
As we know –
↠Momentum = Mass × Speed(Velocity)
↠Momentum = 4 × 3 kgm/s
↠Momentum = 12 kgm/s
- Henceforth,Momentum will be 12 kgm/s.