Answer:
B.
Explanation:
Given that a student runs up a flight of stairs which info is not needed to calculate the rate of the student is doing work against gravity A the height of the flight of stairs B the length of flight of stairs C the time taken to run up the stairs D the weight of the student
The rate of doing work is known as power.
Power = work done/time
Work done = energy = mgh
Since energy = mgh
Where mg = weight
And h = height
Time = time taken to run up the stairs.
Time, weight mg and height h will be needed while the Length of the flight is therefore not needed.
The correct answer is B.
Answer:
The correct answer is option 'c': Smaller stone rebounds while as larger stone remains stationary.
Explanation:
Let the velocity and the mass of the smaller stone be 'm' and 'v' respectively
and the mass of big rock be 'M'
Initial momentum of the system equals

Now let after the collision the small stone move with a velocity v' and the big roch move with a velocity V'
Thus the final momentum of the system is

Equating initial and the final momenta we get

Now since the surface is frictionless thus the energy is also conserved thus

Similarly the final energy becomes
\
Equating initial and final energies we get

Solving i and ii we get

Using this in equation i we get
Thus putting v = -v' in equation i we get V' = 0
This implies Smaller stone rebounds while as larger stone remains stationary.
Answer:
The frictional force acting on the block is 14.8 N.
Explanation:
Given that,
Weight of block = 37 N
Coefficients of static = 0.8
Kinetic friction = 0.4
Tension = 24 N
We need to calculate the maximum friction force
Using formula of friction force

Put the value into the formula


So, the tension must exceeds 29.6 N for the block to move
We need to calculate the frictional force acting on the block
Using formula of frictional force

Put the value in to the formula


Hence, The frictional force acting on the block is 14.8 N.
ANSWER: (ROLE of Producers in the cycle:totake in carbon dioxide from the atmosphere during photosynthesis and release carbon dioxide during respiration,ROLE of Consumers:to contribute to the carbon cycle when they perform respiration and expel carbon dioxide into the atmosphere)
Hope this Helps SOMEONE!!
,Thank you