Initially, the velocity vector is . At the same height, the x-value of the vector will be the same, and the y-value will be opposite (assuming no air resistance). Assuming perfect reflection off the ground, the velocity vector is the same. After 0.2 seconds at 9.8 seconds, the y-value has decreased by
, so the velocity is
.
Converting back to direction and magnitude, we get
Answer:
<em>The force of kinetic friction between Kiera and the floor is 9.24 N</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in rough surfaces, it loses acceleration and/or velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
Where μ is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W
Thus, the friction force is:
Kiera, the W=330 N girl steps in water that has a coefficient of friction of μ=0.028 with the floor.
The kinetic friction force is:
Fr = 0.028*330
Fr = 9.24 N
The force of kinetic friction between Kiera and the floor is 9.24 N
Answer:
T=4.24 N.m
Explanation:
Torque is equal to force for distance for sinus of the angle between the direction of the force and the distance, the distance between the mass and the pivot is 1 m, and to obtain the force that is the mass for the gravity in this case, we need to know the component that produces a torque in the pivot
F=0.5 kg* 9.8 m/= 4.9 N
and we decompose the force in parallel direction to the rod and perpendicular direction to the rod, the magnitude that produces torque is the perpendicular component, because the torque is in function of the sinus
so, we obtain -> Fy= 4.9 N*sin(60)= 4.24 N
and, T= (4.24 N)*(1 m)*(Sin(90))= 4.24 N.m
anothe way to do it is,
T= (4.9 N)*(1 m)*(Sin(60))= 4.24 N.m, and we obtain the same result