Respuesta :
Answer:
(A). The work done on the cart by the friction is -700 J.
(B). The work done on the cart by the gravitational force is 0 J.
(C). The work done on the cart by the shopper is 700 J.
(D). The force the shopper exerts 38.61 N.
(E). The total work done on the cart is zero.
Explanation:
Given that,
Distance = 20.0 m
Frictional force = 35.0 N
Angle = 25.0°
(A). We need to calculate the work done on the cart by the friction
Using formula of work done
[tex]W_{fr} = -F\cdot d[/tex]
Where, F = force
d = distance
Put the value into the formula
[tex]W_{fr}=-35.0\times20[/tex]
[tex]W_{fr}=−700\ J[/tex]
(B). The work done by the gravity is perpendicular to the direction of the motion
We need to calculate the work done on the cart by the gravitational force
Using formula of work done
[tex]W=fd\cos\theta[/tex]
Put the value into the formula
[tex]W=35.0\times20\cos90[/tex]
[tex]W=0\ J[/tex]
(C). We need to calculate the work done on the cart by the shopper
Using formula of work done
[tex]W_{sh}=W_{net}-W_{fr}[/tex]
Put the value into the formula
[tex]W_{sh}=0-(-700)[/tex]
[tex]W_{sh}=700\ J[/tex]
(D). We need to calculate the force the shopper exerts
Using formula of force
[tex]F_{sh}=\dfrac{W_{fr}}{d\cos\theta}[/tex]
Put the value into the formula
[tex]F_{sh}=\dfrac{700}{20\cos25}[/tex]
[tex]F_{sh}=38.61\ N[/tex]
(E). We need to calculate the total work done on the cart
Using formula of work done
[tex]W_{cart}=W_{fr}+W_{sh}[/tex]
Put the value into the formula
[tex]W_{cart}=700-(-700)[/tex]
[tex]W_{cart}=0\ J[/tex]
Hence, (A). The work done on the cart by the friction is -700 J.
(B). The work done on the cart by the gravitational force is 0 J.
(C). The work done on the cart by the shopper is 700 J.
(D). The force the shopper exerts 38.61 N.
(E). The total work done on the cart is zero.
