A scientist can assess whether a pure niobium sample is responsible for contaminating the lab with radioactivity by testing the sample. By testing the niobium sample, a scientist can determine whether it has any other element.
Given:
Acceleration is uniform and acceleration (a) = 10 m/s^2
Now it has been mentioned for the first 2 secs the acceleration is 10m/s^2 .
Hence velocity= acceleration x time
Velocity= 10 x 2 = 20 m/s
Consider s as the distance traveled in the 3rd second.
Now we know s= ut+1/2(at^2)
Where s is the distance measured in m.
u is the initial velocity measured in m/sec
t is the time taken for the object to travel the above distance. This is equal to one second as we need to calculate the distance traveled between 3rd and 2nd second.
t = (3-2)= 1 sec
Substituting the given values in the above formula we get
s = 20 x1 + 1/2 (10 x 1 x 1)
s = 25 m
Thus the distance traveled by the object in the 3rd second is 25 m
Answer:
a) distance d = 293.36ft
b) acceleration a = 14.67ft/s^2
Explanation:
Acceleration is the change in velocity per unit time.
a = ∆v/t ....1
Given;
Initial velocity vi = 30mph × 5280ft/mile × 1/3600s/h
vi = 44ft/s
Final velocity vf = 70mph × 5280ft/mile × 1/3600s/h
vf = 102.67ft/s
time = 4.0s
From equation 1, acceleration is;
a = ∆v/t = (102.67-44)/4 = 14.67ft/s^2
Distance travelled can be given as;
d = ut + 0.5at^2 .....2
u = 44ft/s
t = 4
a = 14.67ft/s^2
Substituting into the equation 2
d = 44(4) + 0.5(14.67×4^2)
d = 293.36ft
When they meet the 40-kg boy will have moved a distance of 6 m.
Displacement of the 40 kg boy
The displacement of the 40 kg boy is calculated from the principle of center mass.
X(40 kg) = (60 x 10 m + 40 x 0)/(40 kg + 60 kg)
X(40 kg) = (600)/(100) = 6 m
X(60 kg) = (60 x 0 + 40 x 10 m)/(40 kg + 60 kg)
X(60 kg) = (400)/(100) = 4 m
Thus, when they meet the 40-kg boy will have moved a distance of 6 m.
Learn more about center mass here: brainly.com/question/13499822
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Answer:
because some waste heat is always produced produced in a heat engine.
Explanation:
the fraction of heat input that is converted to a net work output is a measure of the performance of the heat engine and is called the thermal efficiency.Since the machine does not contain a source of energy ,nor can it store energy ,from this conversation of energy the power output of machine can never be greater than its input,so efficiency can be less than 100%.