Two forces, of magnitudes F_1 = 85.0 N and F_2 = 45.0 N, act in opposite directions on a block, which sits atop a frictionless surface, as shown in the figure. Initially, the center of the block is at position x_i = -4.00 cm. At some later time, the block has moved to the right, and its center is at a new position, x_f = 5.00 cm.
F_1=85*(0.04+0.05)=7.65J
F_2=45*(0.04+0.05)=4.05J
The previous dude is 75% correct. The second answer HAS to be negative since it's moving backwards mate.
To find the net force acting on the block, we need to subtract the force acting in the opposite direction from the force acting in the forward direction.
Given:
F1 = 85.0 N (forward force)
F2 = 45.0 N (opposite force)
xi = -4.00 cm (initial position)
xf = 5.00 cm (final position)
Step 1: Convert the positions from centimeters to meters
xi = -4.00 cm * (1 m / 100 cm) = -0.04 m
xf = 5.00 cm * (1 m / 100 cm) = 0.05 m
Step 2: Calculate the change in position
Δx = xf - xi = 0.05 m - (-0.04 m) = 0.09 m
Step 3: Calculate the net force
The net force (F_net) can be calculated using Newton's second law:
F_net = ma, where m is the mass of the block and a is the acceleration.
Since the block is on a frictionless surface, there is no acceleration (a = 0 m/s^2). This means the net force is equal to 0.
Step 4: Determine the force that is causing the block to move
Since the net force is zero, the forces F1 and F2 must cancel each other out:
F1 + F2 = 0
Plugging in the given values:
85.0 N + 45.0 N = 0
This equation is not satisfied since the sum is not equal to zero. Therefore, there must be some additional force acting on the block or an error in the given information.
To find the net force acting on the block, we need to consider the two forces acting on it and their directions.
Let's assume that the force F1 = 85.0 N is positive in the right direction, and the force F2 = 45.0 N is negative in the left direction.
Since the two forces are acting in opposite directions, we can find the net force by subtracting the magnitude of the smaller force from the magnitude of the larger force, and taking into account their directions.
Net force = |F1| - |F2|
Substituting the given values, we get:
Net force = 85.0 N - 45.0 N
= 40.0 N
Therefore, the net force acting on the block is 40.0 N.
To find the displacement of the block, we can use the following equation:
Displacement = final position - initial position
= xf - xi
= 5.00 cm - (-4.00 cm)
= 9.00 cm
Therefore, the displacement of the block is 9.00 cm to the right.