If the box is moving at constant velocity, net force must be zero, so:
F + fr = 0
fr = -F
<u>fr = -40 N</u>
<u>Answer</u>: The mass of the object is 25kg.
The given question deals with Newton's second law of motion and its applications.
<u>Explanation:</u> Given force, F=500N
acceleration, a=20 m/
From Newton's 2nd law of motion , we have
F=ma where m=mass of the object
⇒500=m×20
⇒m=500/20=25
∴ Mass of the object is 25 kg .
<u> </u><u>Reference Link: </u>brainly.com/question/1141170
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Answer:
age of the site is 15411.75 years old
Explanation:
Given data
plant or animal dies = 14C
time period = 5730 year
carbon = 15.5%
to find out
age (in years) of the ancient site
solution
we know that Final value = Initial value × 
here n is half life passed
so for 15.5%
15.5% = 100% of 
0.155 = 1 × 
now take log both side
log 0.155 = log 
n = log 0.155 / log 0.5
n = 2.68966
we know here 5730 years in half life
so for 2.68966 half-lives = 2.68966 × 5730 = 15411.7518
age of the site is 15411.75 years old
Answer:
139.6m/s
Explanation:
Calculate the tension first, T=m*g
mass(m): 1750kg, gravity(g): 9.8m/s^2
T= 1750*9.8
=17150N
Then calculate the wave speed using the equation v = √ (T/μ)
v= √(17150N)/(0.88kg/m)
=139.6m/s
Answer:
The non-relativistic kinetic energy of a proton is 
The relativistic kinetic energy of a proton is 
Explanation:
Given that,
Mass of proton 
Speed
We need to calculate the kinetic energy for non relativistic
Using formula of kinetic energy

Put the value into the formula


We need to calculate the kinetic energy for relativistic
Using formula of kinetic energy



Hence, The non-relativistic kinetic energy of a proton is 
The relativistic kinetic energy of a proton is 