A red ladybug appears red in white light, red in red light, and black in blue light. Those would be the proper selections you'd need.
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
A model train traveling at a constant speed around a circular track has a constant velocity. FALSE.
Hope this helps you!
Answer:
The moon also falls towards the Earth, but having a tangential speed, the acceleration it has is used in the change of direction of its speed,
Explanation:
Newton explained that all objects attract each other, as the Earth is much greater than the apple, it is this that falls towards the Earth.
The moon also falls towards the Earth, but having a tangential speed, the acceleration it has is used in the change of direction of its speed, in general this acceleration is called centripetal
This principle is used in all circular motion devices, for example the merry-go-round in parks, the radius of the circle is proportional to the speed of the turn and therefore to the centripetal acceleration of the device.