When a footballer collides with the goal post, the forces at work are the action and reaction forces. The player will exert an action force on the goal post, and then a reaction force from the goal post will stop the player. The reaction force call will cause pain and even injury to the player.
The only thing that definitely happens in every such case is:
The container becomes heavier.
Answer:
a = g = 9.81[m/s^2]
Explanation:
This problem can be solve using the second law of Newton.
We know that the forces acting over the skydiver are only his weight, and it is equal to the product of the mass by the acceleration.
m*g = m*a
where:
g = gravity = 9.81[m/s^2]
a = acceleration [m/s^2]
Note: If the skydiver will be under air resistance forces his acceleration will be different.
Answer:
True.
Explanation:
If the sum of the external forces on an object is zero, then the sum of the external torques on it must also be zero.
The net external force and the net external torque acting on the object have to be zero for an object to be in mechanical equilibrium.
Hence, the given statement is true.
Answer:
A. The electric field points to the left because the force on a negative charge is opposite to the direction of the field.
Explanation:
The electric force exerted on a charge by an electric field is given by:
where
F is the force
q is the charge
E is the electric field
We see that if the charge is negative, q contains a negative sign, so the force F and the electric field E will have opposite signs (which means they have opposite directions). This is due to the fact that the direction of the lines of an electric field shows the direction of the electric force experienced by a positive charge in that electric field: therefore, a negative charge will experience a force into opposite direction.
