The power source its getting usually determines its voltage.
initial height of the pole vaulter = 4.2 m
height of the pole vaulter just before it touch the pad = 80 cm
so the total displacement of pole vaulter just before he will touch the pad = 4.2 - 0.80 = 3.4 m
now by kinematics
now after this he will come to rest after compressing the pad by 50 cm
so again we can use kinematics to find its acceleration
so here its acceleration will be - 66.64 m/s^2
Ek = 1/2 mv^2
9 × 10^4 = 1/2 × 800 × v^2
9 × 10^4/400 = 400 v^2 / 400
9 × 10^4/400 = v^2
√225 = v
15 ms⁻¹ = v
That's the only way I know how to work it out
I think in this case velocity and speed would be considered the same because me
s = d/t and v=d/t
one is distance travelled and the other is displacement of a body
Answer:
0.0107
Explanation:
We know that
The rotational kinetic energy due to four wheel is
1/2ဃ²I x 4
So
1/4mR²(v/R)² = mv²
But kinetic energy along straight path of the car is 1/2mv²
=> 1/2( 817)v ²
Kc= 408.5v²
So The fraction of total kinetic energy that is due to rotation of the wheel about their axis
Is Kw/Kw+Kc
and Kw = 1/2* 8.91v²= 4.45v²
So 4.45v²/ 4.45v²+ 408.5v²
= 0.0107 as fraction of total kinetic energy
