Power P is the rate at which energy is generated or consumed and hence is measured in units that represent energy E per unit time t. This is:
P = E/t
Solving for t:
t = E/P
t = 6007 J / 500 W
t = 12.014 s
<h2>
t ≅ 12 s</h2>
Answer:
(a) The horizontal ground reaction force
(b) The vertical ground reaction force
(c) The resultant ground reaction force
Explanation:
Given
John mass , m = 65 kg
Horizontal acceleration ,
Vertical acceleration ,
(a) Using Newton's 2nd law in horizontal direction
=>
Thus the horizontal ground reaction force
(b) Using Newton's 2nd law in vertical direction
=>
=>
Thus the vertical ground reaction force
(c) Resultant ground reaction force is
=>
=>
Thus the resultant ground reaction force
Answer:
kinetic friction may be greater than 400 N or smaller than 400 N
Explanation:
As we know that maximum value of static friction on the rough surface is known as limiting friction and the formula of this limiting friction is known as
now when object is sliding on the rough surface then the friction force on that surface is known as kinetic friction and the formula of kinetic friction is known as
now we know that
so here value of limiting static friction force is always more than kinetic friction
also we know that
initially when body is at rest then static friction value will lie from 0 N to maximum limiting friction
and hence kinetic friction may be greater than static friction or if the static friction is maximum limiting friction then kinetic friction is smaller than static friction
so kinetic friction may be greater than 400 N or smaller than 400 N