Answer:
6.0 m/s
Explanation:
According to the law of conservation of energy, the total mechanical energy (potential, PE, + kinetic, KE) of the athlete must be conserved.
Therefore, we can write:
![KE_i+PE_i =KE_f+PE_f](https://tex.z-dn.net/?f=KE_i%2BPE_i%20%3DKE_f%2BPE_f)
or
![\frac{1}{2}mu^2+0=\frac{1}{2}mv^2+mgh](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7Dmu%5E2%2B0%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2%2Bmgh)
where:
m is the mass of the athlete
u is the initial speed of the athlete (at the bottom)
0 is the initial potential energy of the athlete (at the bottom)
v = 0.80 m/s is the final speed of the athlete (at the top)
is the acceleration due to gravity
h = 1.80 m is the final height of the athlete (at the top)
Solving the equation for u, we find the initial speed at which the athlete must jump:
![u=\sqrt{v^2+2gh}=\sqrt{0.80^2+2(9.8)(1.80)}=6.0 m/s](https://tex.z-dn.net/?f=u%3D%5Csqrt%7Bv%5E2%2B2gh%7D%3D%5Csqrt%7B0.80%5E2%2B2%289.8%29%281.80%29%7D%3D6.0%20m%2Fs)
Answer:
Work done = 35467.278 J
Explanation:
Given:
Height of the cone = 4m
radius (r) of the cone = 1.2m
Density of the cone = 600kg/m³
Acceleration due to gravity, g = 9.8 m/s²
Now,
The total mass of the cone (m) = Density of the cone × volume of the cone
Volume of the cone = ![\frac{1}{3}\pi r^2 h](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7D%5Cpi%20r%5E2%20h)
thus,
volume of the cone =
= 6.03 m³
therefore, the mass of the cone = 600 Kg/m³ × 6.03 m³ = 3619.11 kg
The center of mass for the cone lies at the
times the total height
thus,
center of mass lies at, h' = ![\frac{1}{4}\times4=1m](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4%7D%5Ctimes4%3D1m)
Now, the work gone (W) against gravity is given as:
W = mgh'
W = 3619.11kg × 9.8 m/s² × 1 = 35467.278 J
A water wave is an example of a mechanical wave. A wave that can travel only through matter is called a mechanical wave.
Answer:
the plot structure defines a story's setting