Please help me with this question. Every help is appreciated.

A factory worker pushes a 30.0-kg crate a distance of 4.5 m along a level floor at constant velocity by pushing horizontally on

Olin [163]

The crate moves at constant velocity, this means that its acceleration is zero, so the net force acting on the crate is zero (Newton's second law).

There are only two forces acting on the crate: the force F applied by the worker and the frictional force, acting in the opposite direction: $\mu m g$ , where $\mu=0.25$ is the coefficient of friction and $m=30.0 kg$ is the mass of the crate. Since the net force should be equal to zero, the two forces must have same magnitude, so we have:
$F=\mu m g=(0.25)(30.0 kg)(9.81 m/s^2)=73.8 N$
And so, this is the force that the worker must apply to the crate.

5 0

3 years ago

What does this mean?

Alexeev081 [22]

Well, in some systems the atoms melt or burn or change state like from liquid to gases when they reach a certain temperature. This could decrease the energy in the system.
Hope I helped

3 0

3 years ago

A shot-putter released the shot at an angle of 41.5 degrees and a height of 1.9 m with an initial velocity of 13.3 m/s. How far

liq [111]

Answer:

x = 17.88[m]

Explanation:

We can find the components of the initial velocity:

$(v_{x})_{o} = 13.3*cos(41.5)=9.96[m/s]\\(v_{y})_{o} = 13.3*sin(41.5)=8.81[m/s]$

We have to remember that the acceleration of gravity will be worked with negative sign, since it acts in the opposite direction to the movement in direction and the projectile upwards.

g = - 9.81[m/s^2]

Now we must find the time it takes for the projectile to hit the ground, as the problem mentions that it does not impact on the board.

$y=y_{o} +(v_{y} )_{o} *t-0.5*g*(t)^{2} \\0=1.9+(8.81*t)-(4.905*t^{2})\\-1.9=8.81*t*(1-0.5567*t)\\t=0\\t=1.796[s]$

With this time we can calculate the horizontal distance:

$x=(v_{x})_{o} *t\\x=9.96*1.796\\x=17.88[m]$

3 0

3 years ago

A vehicle of known mass accelerates along a straight path. According to Newton's second law of motion, what caused this accelera

Naily [24]

The answer would be:

C. An unbalanced force has acted on the vehicle.

The presence of an unbalanced force will accelerate an object, the second law of motion dictates this (Although not explicitly). Lets knock out the rest of the choices.

If a balance force acted on the vehicle, then the vehicle would be at rest. The mass of the vehicle did not change (Unless it falls apart, which I doubt). The direction of the vehicle does not change and it will only do so if another force and a stronger one at that will counteract the current net force acting on the vehicle.

Hope you got your answer here, although you did not ask for an explanation, maybe this will help you figure some of the other questions you have on your own.

6 0

3 years ago

Read 2 more answers

The "Garbage Project" at the University of Arizona reports that the amount of paper discarded by households per week is normally

Lorico [155]

Answer:

54%

Explanation:

We are given that

S.D=4.2 lb

Mean= $\mu=9.4 lb$