a man pushes a packing case which has a total mass of 50 kg across a floor at a constant speed of 0.4 m s-1 by exerting a horizontal force of 100 N.
(a) what was the resultant force on the case?
> F = ma
F = 50 * 0
F =0
(b) what was the frictional force acting on the case?
> 0 (frictional force is the same as resultant force?)
(c) if the force exerted by the man is increased to 120 N, what will the acceleration be?
> F = ma
120 = 50 * a
a = 120 / 50
a = 2.4 m s-2
friction force=100, constant speed
120-100=ma
solve for a
(a) The resultant force on the case is 0 N. This is because the case is moving at a constant speed, which means there is no acceleration and therefore no net force acting on it.
(b) The frictional force acting on the case is also 0 N. In this case, the frictional force is equal in magnitude and opposite in direction to the applied force. Since the case is moving at a constant speed, the applied force and the frictional force must cancel each other out.
(c) If the force exerted by the man is increased to 120 N, the acceleration of the case can be calculated using the equation F = ma. Plugging in the values:
120 N = 50 kg * a
Solving for a:
a = 120 N / 50 kg
a ≈ 2.4 m/s²
So the acceleration of the case would be approximately 2.4 m/s².
(a) The resultant force on the case can be found using Newton's second law, which states that force is equal to mass multiplied by acceleration (F = ma). In this case, the mass of the packing case is 50 kg and the speed is constant, meaning there is no acceleration. Therefore, the resultant force on the case is 0 N.
(b) The frictional force acting on the case can be determined by subtracting the applied force (resultant force) from the horizontal force exerted by the man. Since the resultant force is 0 N as calculated in part (a), the frictional force will also be 0 N in this scenario.
(c) If the force exerted by the man is increased to 120 N, we can use Newton's second law again to find the acceleration. Rearranging the equation (F = ma), we can solve for acceleration (a) by dividing the applied force (120 N) by the mass of the packing case (50 kg). Therefore, the acceleration will be 2.4 m/s².