Answer:
F = 120 N
Explanation:
Given that,
The mass of a runner, m = 60 kg
Acceleration of the runner, a = 2 m/s²
We need to find the force provided from her legs. The formula for force is given by :
F = ma
Substitute all the values,
F = 60 kg × 2 m/s²
= 120 N
So, the required force is equal to 120 N.
Use F=ma formula
F=m v/t. a=v/t
put values u will get answer.
answer should be around 30N .
Answer:
E = - dV / dx
Explanation:
The equipotential lines are lines or surfaces that have the same power, therefore we can move in them without carrying out work between equipotential lines, work must be carried out, therefore the electric field changes.
The electric field and the potential are related by
E = - dV / dx
therefore when the change is faster, that is, the equipotential lines are closer, the greater the electric field must be.
Energy is never created and energy never is destroyed
Since the acceleration is constant, the average velocity is simply the average of the initial and final velocities of the body:
![v_{avg} = \frac{v_f+v_i}{2}=\frac{30 m/s+13 m/s}{2}=21.5 m/s](https://tex.z-dn.net/?f=v_%7Bavg%7D%20%3D%20%5Cfrac%7Bv_f%2Bv_i%7D%7B2%7D%3D%5Cfrac%7B30%20m%2Fs%2B13%20m%2Fs%7D%7B2%7D%3D21.5%20m%2Fs)
We can proof that the distance covered by the body moving at constant average velocity
is equal to the distance covered by the body moving at constant acceleration a:
- body moving at constant velocity
: distance is given by
![S=v_{avg}t = \frac{v_f+v_i}{2}t](https://tex.z-dn.net/?f=S%3Dv_%7Bavg%7Dt%20%3D%20%5Cfrac%7Bv_f%2Bv_i%7D%7B2%7Dt)
- body moving at constant acceleration
: distance is given by
![S=v_i t+ \frac{1}{2}at^2 = v_i t + \frac{1}{2}\frac{v_f-v_i}{t}t^2=(v_i+\frac{1}{2}(v_f-v_i))t=\frac{v_f+v_i}{2}t](https://tex.z-dn.net/?f=S%3Dv_i%20t%2B%20%5Cfrac%7B1%7D%7B2%7Dat%5E2%20%3D%20v_i%20t%20%2B%20%5Cfrac%7B1%7D%7B2%7D%5Cfrac%7Bv_f-v_i%7D%7Bt%7Dt%5E2%3D%28v_i%2B%5Cfrac%7B1%7D%7B2%7D%28v_f-v_i%29%29t%3D%5Cfrac%7Bv_f%2Bv_i%7D%7B2%7Dt)