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
Answer:
Regardless of how the steps are documented, the goal of scientific method is to gather data that will validate or invalidate a cause and effect relationship.
Hope this helped!!!
Answer:
Block A
Explanation:
Block A will float higher in the water compared to the second Block.
The density of water is 1g/cm³.
According to the principle of floatation "an object that floats in a liquid will displace equal amount of fluid to the weight of the object".
A body will become more submerged in water if it has more density because density is the mass per volume of body.
An object with a higher density than another will sink in the liquid of the one with lesser density.
- Object A has lesser density and will float higher up and displace very little water.
- Object B has higher density and will be more submerged.
Answer:
Explanation:
P = 50 N
Q = 30 N
= Angle between the vectors = 
Resultant is given by
Angle of resultant
Magnitude of the resultant is
Direction of the resultant is
