Your moving company is to load a crate of books on a truck with the help of some planks that slope upward at The mass of the crate is 100 kg, and the coefficient of sliding friction between it and the planks is 0.500. You and your employees push horizontally with a combined net force Once the crate has started to move, how large must F be in order to keep the crate moving at constant speed?

Respuesta :

Answer:

the force must be larger than F= 490N for example for a speed of 1m/s for 10s the force is 590N

Explanation:

The motion of the truck must be bigger than the Fk of friction that is opposite of the force both person are doing so:

[tex]F-F_{k}=m*a[/tex]

Knowing the truck must be accelerated to get a constant speed the acceleration can be determinate by

[tex]V_{f}=V_{o}+a*t[/tex]

It is at rest so

[tex]V_{f}=a*t[/tex]

[tex]a=\frac{V_{f}}{t}[/tex]

The force net of both person is

[tex]F<F_{k}[/tex]

[tex]F=u_{k}*m*g[/tex]

[tex]F=0.5*100kg*9.8\frac{m}{s^2}[/tex]

[tex]F=490N[/tex]

Asume for example that the speed they want is about 1 m/s for 10 s so the force have to be larger than 490N

[tex]F=m*(\frac{V_{f}}{t}+m*g )[/tex]

[tex]F=100kg*(1\frac{m}{s}}+0.5*9.8\frac{m}{s^2})[/tex]

[tex]F=590N[/tex]