Answer:
Explanation:
I hate these kinds of problems, luckily I can't understand how much the kinetic friction is for this , the words are all mixed around. and don't read well. Maybe this went through a translator program? My suggestion draw the free body diagram. so you can see where the forces are, and how they are acting. getting the free body diagram right.. usually makes these problems pretty straight forward. just do the steps and you get the answer.
Answer:
a 
b 
Explanation:
Generally the force constant is mathematically represented as
substituting values given in the question
=> 
=> 
Generally the workdone in stretching the spring 3.5 m is mathematically represented as
=> 
=>
Generally the workdone in compressing the spring 2.5 m is mathematically represented as
=> 
=>
Answer:
Explanation:
A 40kg child throw stone of 0.5kg
At a direction of 5m/s
Recoil can be calculated using recoil of a gun formula
m_1•v_1 + m_2•v_2
m_1•v_1 = -m_2•v_2
The negative sign show that the momentum of the boy is directed oppositely to that of the stone
m_1 Is mass of boy
v_1 is the recoil velocity of the boy
m_2 is mass of stone
v_2 is the velocity of stone
Then,
m_1•v_1 = -m_2•v_2
40•v_1 = -0.5 × 5
40•v_1 = -2.5
v_1 = -2.5 / 40
v_1 = -0.0625 m/s
The recoil velocity of the boy is 0.0625 m/s
