If positive work is being done to an object...

A car travels on a straight, level road. (a) Starting from rest, the car is going 38 ft/s (26 mi/h) at the end of 4.0 s. What is

lbvjy [14]

Answer:

$a)9.5\frac{ft}{s^2}\\ b) 12.66\frac{ft}{s^2}$

Explanation:

A body has acceleration when there is a change in the velocity vector, either in magnitude or direction. In this case we only have a change in magnitude. The average acceleration represents the speed variation that takes place in a given time interval.

a)

$a_{avg}=\frac{\Delta v}{\Delta t}\\a_{avg}=\frac{v_{f}-v_{i}}{t_{f}- t_{i}}\\a_{avg}=\frac{38\frac{ft}{s}-0}{4 s- 0}=9.5\frac{ft}{s^2}\\$

b)

$a_{avg}=\frac{\Delta v}{\Delta t}\\a_{avg}=\frac{v_{f}-v_{i}}{t_{f}- t_{i}}\\a_{avg}=\frac{76\frac{ft}{s}-38\frac{ft}{s}}{7 s- 4s}\\a_{avg}=\frac{38\frac{ft}{s}}{3s}=12.66\frac{ft}{s^2}$

8 0

3 years ago

Two points charges are brought closer together,increasing the force between them by a factor of 25.By what factor wa their separ

Roman55 [17]

Answer:

The separation between the charges was decreased by a factor of 0.2

Explanation:

The Coulomb's force between two charges is given by;

$F = \frac{kq^2}{r^2} \\\\let \ kq^2 \ be \ constant\\\\F_1r_1^2 = F_2r_2^2\\\\r_2^2 = \frac{F_1r_1^2}{F_2} \\\\increasing \ the \ force \ between \ them \ by \ factor \ of \ 25\\\\(F_2 = 25F_1)\\\\r_2^2 = \frac{F_1r_1^2}{25F_1}\\\\r_2^2 = \frac{r_1^2}{25}\\\\r_2 = \sqrt{\frac{r_1^2}{25} }\\\\ r_2 = \frac{r_1}{5}$

r₂ = 0.2r₁

Therefore, the separation between the charges was decreased by a factor of 0.2.

6 0

3 years ago

How do officers in this line of work need to use problem solving and critical thinking to do their jobs?

belka [17]

Answer:

by using problem solving skills they could solve who,what,where did the crime oriented. and using critical thinking is good for you to get the job done!

Explanation:

I'm in forensic science :)

8 0

3 years ago

Three boys of equal strength try to break a rope (and fail) by tying one end to a fence post and tugging on the other end. Three

podryga [215]

The best choice would be C. Keep one end of the rope tied to the post and have all six boys tug on the other end.

Reason:

A is not correct since in the first case which is B, untying the rope from the post and have 3 boys on each end of it tug, will provide equal or a near equal amount of tension since the boys are all within the same strength, however there can be variables that will affect the tension.

That means B would be true according to A, and then for C, having all six boys pull on the other end of the rope would provide greater tension, since if 3 boys of the same strength range can't break the rope when its tied to the fence, we add the other 3 boys of the same strength.

However, if 3 boys are on each end of the rope and of the same strength then the rope will not break since there is an equal amount of net force exerted on the rope.

We know that the fence can withstand the strength of 3 boys but if we add the other 3 boys then it could provide us with a different outcome.

3B < F

3B(2) ≥ F

So, therefore, our best choice would be C since A and B is incorrect.

4 0

3 years ago

The difference between a need and a want gets blurry for some people because of:

Anna [14]

The answer should be all of the above

4 0

2 years ago