Answer: 3.41 s
Explanation:
Assuming the question is to find the time
the ball is in air, we can use the following equation:

Where:
is the final height of the ball
is the initial height of the ball
is the initial velocity of the ball
is the time the ball is in air
is the acceleration due to gravity

Then:


Multiplying both sides of the equation by -1 and rearranging:

At this point we have a quadratic equation of the form
, which can be solved with the following formula:
Where:
Substituting the known values:
Solving the equation and choosing the positive result we have:
This is the time the ball is in air
the answer is heat engine
<span>the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.</span>
Answer:
A. 243 N
Explanation:
Friction is the force that opposes the relative motion between systems that are in contact.
This friction force that opposes the motion of the oak chest across the oak surface will be equal and opposite to that exerted by the woman.
First find the normal force which is the force that would point directly upwards to support weight of the block.
Normal force, N= mg where m is the mass of the chest and g is the acceleration due to gravity.
Given m=40 kg and g=9.80 m/s²
N force=40×9.80 =392N
Then find the force of friction which is given by the formula;
<em>F=μN where μ is friction coefficient for the oak chest and N is the normal force on the chest</em>
Given <em>μ</em>=0.620 and N force = 392 N then it will be;
F=0.620× 392 =243.04 N
Answer : 243 N