Explanation:
Work done by winch = kinetic energy of car
∫ T ds = ½ mv²
∫ 225s ds = ½ mv²
225/2 s² = ½ mv²
225 s² = mv²
v = 15s / √m
Given s = 10 m and m = 2500 kg:
v = 15 (10) / √2500
v = 3 m/s
Answer:
44.09 pounds
Explanation:
We got that 20 % of the mass of a nutty chocolate bar its pecans, if 4.0 kg of pecans were used, we need to find the X in the equation

where X its the total mass of nutty chocolate bars produced. So, we can just divide by 0.2 on both sides, and we find:


Of course, we need the total mass produced in pounds, and not in kilograms. Looking at an conversion table, we can find that 1 kg its 2.20462 pounds, multiplying the value for total mass produced by the conversion factor we get:


Now, we just need to round off to two significant figures. This is:
,
the total mass of nutty chocolate bars made last Tuesday to two significant figures.
Answer:
The maximum speed at which the car can safety travel around the track is 18.6m/s.
Explanation:
Since the car is in circular motion, there has to be a centripetal force
. In this case, the only force that applies for that is the static frictional force
between the tires and the track. Then, we can write that:

And since
and
, we have:

Now, if we write the vertical equation of motion of the car (in which there are only the weight and the normal force), we obtain:

Substituting this expression for
and solving for
, we get:

Finally, plugging in the given values for the coefficient of friction and the radius of the track, we have:

It means that in its maximum value, the speed of the car is equal to 18.6m/s.