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A dockworker loading crates on a ship finds that a 20 kg crate, initially at rest on a horizontal surface, requires a 70 N horiz

frez [133]

The coefficient of static friction is 0.357 and the coefficient of kinetic friction is 0.265.

Explanation:

Coefficient of static friction is defined as the proportionality constant for the frictional force between the crate and floor for starting the motion of crate and normal force acting on the crate. As the normal force of the crate is equal to the influence of acceleration due to gravity acting on the mass of the crate, the frictional force for static friction coefficient will be the force applied to move the crate.

Thus, $Static friction force = Coefficient of static friction * Normal force\\\\$

Since, the static friction force is 70 N, the normal force is equal to $Mass * acceleration due to gravity = 20 * 9.8 = 196 N$

So normal force is 196 N and static force is 70 N, and the ratio of static friction force to the normal force will give the coefficient of static friction.

$Coefficient of static friction = \frac{Static friction force}{Normal force}\\ \\Coefficient of static friction = \frac{70}{196} = 0.357$

Similarly, the coefficient of kinetic friction can be determined from the ratio of kinetic friction force to normal force. Here the kinetic friction force will be equal to the force applied on the crate to keep it moving.

$Coefficient of kinetic friction = \frac{Kinetic friction force}{Normal force}\\ \\Coefficient of kinetic friction = \frac{52}{196} = 0.265$

Thus, the coefficient of static friction is 0.357 and the coefficient of kinetic friction is 0.265.

6 0

3 years ago

A car goes from a speed of 10m/s to 30m/s over 4s. If the car has a mass of 1000kg, How strong is the force pushing the car forw

dusya [7]

Answer:

i think ww

Explanation:

i think we need to calculate net force which is:

net force=m.a

..nf=1000kg×30m/s

therefore net force will be the answer you get whwn you multiply those two

5 0

3 years ago

Which changes would most likely limit the growth of a plant-eating animal population

BabaBlast [244]

Probably the changes in environment....

8 0

3 years ago

Margy is trying to improve her cardio endurance by performing an exercise in which she alternates walking and running 100.0 m ea

madreJ [45]

In order to answer this exercise you need to use the formulas

S = Vo*t + (1/2)*a*t^2

Vf = Vo + at

The data will be given as

Vf = final velocity = ?

Vo = initial velocity = 1.4 m/s

a = acceleration = 0.20 m/s^2

s = displacement = 100m

And now you do the following:

100 = 1.4t + (1/2)*0.2*t^2

t = 25.388s

and

Vf = 1.4 + 0.2(25.388)

Vf = 6.5 m/s

So the answer you are looking for is 6.5 m/s

7 0

3 years ago

Read 2 more answers

If a m = 74.7 kg m=74.7 kg person were traveling at v = 0.800 c v=0.800c , where c c is the speed of light, what would be the ra

igomit [66]

Answer:

$\frac{E}{E_c} =3.125$