The answer is always true a
Question:
A 63.0 kg sprinter starts a race with an acceleration of 4.20m/s square. What is the net external force on him? If the sprinter from the previous problem accelerates at that rate for 20m, and then maintains that velocity for the remainder for the 100-m dash, what will be his time for the race?
Answer:
Time for the race will be t = 9.26 s
Explanation:
Given data:
As the sprinter starts the race so initial velocity = v₁ = 0
Distance = s₁ = 20 m
Acceleration = a = 4.20 ms⁻²
Distance = s₂ = 100 m
We first need to find the final velocity (v₂) of sprinter at the end of the first 20 meters.
Using 3rd equation of motion
(v₂)² - (v₁)² = 2as₁ = 2(4.2)(20)
v₂ = 12.96 ms⁻¹
Time for 20 m distance = t₁ = (v₂ - v ₁)/a
t₁ = 12.96/4.2 = 3.09 s
He ran the rest of the race at this velocity (12.96 m/s). Since has had already covered 20 meters, he has to cover 80 meters more to complete the 100 meter dash. So the time required to cover the 80 meters will be
Time for 100 m distance = t₂ = s₂/v₂
t₂ = 80/12.96 = 6.17 s
Total time = T = t₁ + t₂ = 3.09 + 6.17 = 9.26 s
T = 9.26 s
The volume of the balloon will halve
Explanation:
Boyle's law states that for an ideal gas kept at constant temperature, the pressure of the gas is proportional to its volume. Mathematically,
where
p is the gas pressure
V is the volume
The equation can also be rewritten as
And if we apply it to the gas inside the balloon in this problem (assuming its temperature is constant), we have:
is the initial pressure at sea level (the atmospheric pressure)
is the initial volume
is the final pressure
is the final volume
Substituting into the equation, we find:
Which means that the volume of the balloon will halve.
Learn more about ideal gases:
brainly.com/question/9321544
brainly.com/question/7316997
brainly.com/question/3658563
#LearnwithBrainly
Answer:
m≈501.57 g
Explanation:
The density formula is:
d=m/v
Let’s rearrange the formula for m. m is being divided by v. The inverse of division is multiplication, so multiply both aides by v.
d*v= m/v*v
d*v=m
The mass can be found by multiply the density and the volume.
m=d*v
The density is 1.06 grams per milliliter and the volume is 473.176 milliliters.
d= 1.06 g/mL
v= 473.176 mL
Substitute the values into the formula.
m= 1.06 g/mL * 473.176 mL
Multiply. When multiplying, the mL will cancel out.
m= 501.56656 g
Let’s round to the nearest hundredth. The 6 in the thousandth place tells us to round the 6 to a 7 in the hundredth place.
m ≈501.57 g
The mass is about 501.57 grams.
Answer:
The number of atoms is 
Explanation:
From the question we are told that
The mass of coin is 
Number of atom in one mole = 
Molar mass of nickel 
Now the relation to obtain the number of atom in the nickel coin is
