Answer:
The equivalent stiffness of the string is 8.93 N/m.
Explanation:
Given that,
Spring stiffness is





According to figure,
and
is in series
We need to calculate the equivalent
Using formula for series


Put the value into the formula


k and
is in parallel
We need to calculate the k'
Using formula for parallel

Put the value into the formula


,k' and
is in series
We need to calculate the equivalent stiffness of the spring
Using formula for series

Put the value into the formula


Hence, The equivalent stiffness of the string is 8.93 N/m.
In this problem we have the electric field intensity E:
E = 6.5 ×
newtons/coulomb
We have the magnitude of the load:
q = 6.4 ×
coulombs
We also have the distance d that the load moved in a direction parallel to the field 1.2 ×
meters.
We know that the electric potential energy (PE) is:
PE = qEd
So:
PE = (6.4 ×
)(6.5 ×
)(1.2 ×
)
PE = 5.0 x
joules
None of the options shown is correct.
1. its must be B and 2. must be C
Amount of work done is zero and so power = 0 watts.
<u>Explanation:</u>
Power is the rate at which work is done, or W divided by delta t. Since the barbell is not moving, the weightlifter is not doing work on the barbell.Therefore, if the work done is zero, then the power is also zero.It may seem unusual that the data given in question is versatile i.e. A weightlifter exerts an upward force on a 1000-N barbell and holds it at a height of 1 meter for 2 seconds. But, still the answer is zero watts , this was a tricky question although conceptual basis of question was good! Power is dependent on amount of work done which is further related to displacement and here the net displacement is zero ! Hence, amount of work done is zero and so power = 0 watts.
Answer:
t = 7,8 s
Explanation:
From the instant, the rabbit passes the cat. The cat star running acceleration of 0,5 m/s² .
When the cat arrives at the speed of 3,9 m/s the cat catches the rabbit
Then for the cat arrives at 3,9 m/s nedds
v = vo + a*t vo = 0 then v = a*t
3,9 ( m/s) = 0,5 ( m/s² ) * t
t = 7,8 s
v = 3,9 m/s =