I assume the block plows into the bank of sand with a velocity of 6 m/s and comes to a stop in 2 s.
1)
Answer:
Part 1)
H = 30.6 m
Part 2)
t = 2.5 s
Part 3)
t = 2.5 s
Part 4)

Explanation:
Part 1)
initial speed of the ball upwards

so maximum height of the ball is given by



Part 2)
As we know that final speed will be zero at maximum height
so we will have



Part 3)
Since the time of ascent of ball is same as time of decent of the ball
so here ball will same time to hit the ground back
so here it is given as
t = 2.5 s
Part 4)
since the acceleration due to earth will be same during its return path as well as the time of the motion is also same
so here its final speed will be same as that of initial speed
so we have

2)
Answer:
a = 9.76 m/s/s
Explanation:
As we know that the object is released from rest
so the displacement of the object in vertical direction is given as



3)
Answer:
v = 29.7 m/s
Explanation:
acceleration of the rocket is given as

time taken by the rocket
t = 0.33 min
final speed of the rocket is given as



4)
Answer:
Part 1)
y = 25.95 m
Part 2)
d = 6.72 m
Explanation:
Part 1)
As it took t = 2.3 s to hit the water surface
so here we will have



Part 2)
Distance traveled by it in horizontal direction is given as



Answer:
the molecular formula for the gas is NO₂
Explanation:
since it contains
Nitrogen = n → 30.45%
Oxygen = o → 69.55%
and 30.45%+69.55% = 100% , then the gas only contains nitrogen and oxygen
Also we know that the proportion of oxygen over nitrogen is
proportion of oxygen over nitrogen = moles of oxygen / moles of nitrogen
since
moles = mass / molecular weight
then for a sample of 100 gr of the unknown gas
mass of oxygen = 69.55%*100 gr = 69.55 gr
mass of Nitrogen = 30.45%*100 gr = 30.45 gr
proportion of oxygen over nitrogen = (mass of oxygen/ molecular weight)/(mass of nitrogen / molecular weight of nitrogen ) = (69.55 gr/ 16 gr/mol) /( 30.45 gr /14 gr/mol) = 1.998 mol of O/ mol of N≈ 2 mol of O/ mol of N
therefore there are 2 atoms of oxygen per atom of nitrogen
thus the molecular formula for the gas is:
NO₂
First of all, we need to convert the angular speed from rev/min into rev/s:

The angular acceleration is the variation of angular speed divided by the time:

And this is constant, so we can use the following equation to calculate the angle through which the engine has rotated:

so, 5 revolutions.
The change in the state of matter causes change in the motion of the particles of the matter. The gaseous state of matter has the greatest speed while the solid state has the least speed.
The change in state of every matter is accompanied by lost or gained of energy.
Example is water.
The solid state of water is ice. The motion of particles of the water is relatively zero because the molecules are held at a fixed position.
The liquid state of water occurs when the temperature of the ice is increased above zero degree Celsius. The speed of the particles of water in liquid state is greater than solid state.
The gaseous state of water occurs when the temperature of the liquid water is increased beyond 100 degree Celsius. The speed of water in gaseous state is greater than liquid state.
Learn more about different state of matter here: brainly.com/question/9402776