Answer:
<em>The coefficient of static friction between the crate and the floor is 0.41</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in the air or rough surfaces, it loses acceleration and velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
[1]
Where 
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 = m.g
The crate of m=20 Kg has a weight of:
W = 20*9.8
W = 196 N
The normal force is also N=196 N
We can find the coefficient of static friction by solving [1] for :
The friction force is equal to the minimum force required to start moving the object on the floor, thus Fr=80 N and:
The coefficient of static friction between the crate and the floor is 0.41
Answer:
They developed during the Cambrian time period, which was around 530 million years ago.
Explanation:
Hope this Helps!
Answer:
a. 12 m/s² down
Explanation:
Acceleration has units of length per time squared. Acceleration is a vector, so it also has a direction.
Answer:
The time taken will be 0.553 seconds.
Explanation:
We should start off by finding the force exerted by the rope on the 3kg weight in this case.
Weight of 5kg mass = 5 * 9.81 = 49.05 N
Weight of 3kg mass = 3 * 9.81 = 29.43 N
The force acting upward on the 3kg mass will equal the weight of the 5kg mass. Thus the resultant force acting on the 3kg mass is:
Total force = 49.05 - 29.43 = 19.62 N (upwards)
We can now find the acceleration:
F = m * a
19.62 = 3 * a
a = 6.54 m/s^2
We now use the following equation of motion to get the time taken to travel 1 meter:
t = 0.553 seconds
