Respuesta :
Answer:
(a) 50 kJ
(b) 14.14 m/s
(c) 0 N
(d) 0 J
Solution:
As per the question:
Mass of car, m = 500 kg
Force, F = 1000 N
Distance traveled, s = 50 m
Now,
(a) The total work done can be given as:
[tex]W = F\times s = 1000\times 50 = 50000\ J = 50\ kJ[/tex]
(b) To calculate the speed of the car:
Using work-energy relation, we can say that the work done equals the change in the kinetic energy of the car:
[tex]W = \Delta KE[/tex]
[tex]\frac{1}{2}m(v'^{2} - v^{2}) = 50000[/tex]
where
v' = final velocity
v = initial velocity = 0
Now,
[tex]\frac{1}{2}\times 500v'^{2} = 50000[/tex]
[tex]v' = \sqrt{200} = 14.14\ m/s[/tex]
(c) To calculate the net force on the car when the velocity is constant:
The net force is given as the product of mass and acceleration:
F = ma
Acceleration can be defined as the rate with which the velocity of the car changes and the since the velocity is constant, the car will not have any acceleration, a = 0
Thus the net force is also zero.
[tex]F_{net} = 500\times 0 = 0\ N[/tex]
(d) The total work done when the car moves with constant velocity:
[tex]W = F_{net}.s = 0\ J[/tex]
