Answer:
speed of the bullet before it hit the block is 200 m/s
Explanation:
given data
mass of block m1 = 1.2 kg
mass of bullet m2 = 50 gram = 0.05 kg
combine speed V= 8.0 m/s
to find out
speed of the bullet before it hit the block
solution
we will apply here conservation of momentum that is
m1 × v1 + m2 × v2 = M × V .............1
here m1 is mass of block and m2 is mass of bullet and v1 is initial speed of block i.e 0 and v2 is initial speed of bullet and M is combine mass of block and bullet and V is combine speed of block and bullet
put all value in equation 1
m1 × v1 + m2 × v2 = M × V
1.2 × 0 + 0.05 × v2 = ( 1.2 + 0.05 ) × 8
solve it we get
v2 = 200 m/s
so speed of the bullet before it hit the block is 200 m/s
Answer:

Explanation:
Given:
- mass of John,

- mass of William,

- length of slide,

(A)
height between John and William, 
<u>Using the equation of motion:</u>

where:
v_J = final velocity of John at the end of the slide
u_J = initial velocity of John at the top of the slide = 0
Now putting respective :


<u>Now using the law of conservation of momentum at the bottom of the slide:</u>
<em>Sum of initial momentum of kids before & after collision must be equal.</em>

where: v = velocity with which they move together after collision

is the velocity with which they leave the slide.
(B)
- frictional force due to mud,

<u>Now we find the force along the slide due to the body weight:</u>



<em><u>Hence the net force along the slide:</u></em>

<em>Now the acceleration of John:</em>



<u>Now the new velocity:</u>



Hence the new velocity is slower by

Without an atmosphere, the equatorial curve would show minimum daily values on the solstices in June when the sub-solar point is located at 23.5°N and in December when the sub-solar point is at 23.5°S latitude.
Explanation:
At the sub-solar point, the sun strikes directly at the surface with an angle of 90 degrees at a given point.
Solistice refers to that point in time when the sun’s zenith is located at the farthest point from the equator.
During summer solistice on June 21, the sun’s zenith reaches northernmost point, sub-solar point is fixed at 23.5°S Tropic of Cancer making the earth tilt 23.4 degrees
During winter soliscitse on December 21, the sub-solar point is fixed at) Tropic of Capricorn.
Look at the title of the graph, in small print under it.
Each point is "compared to 1950-1980 baseline". So the set of data for those years is being compared to itself. No wonder it matches up pretty close !