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2 years ago

True or False?

Physics

2 answers:

snow_lady [41]2 years ago

6 0

It’s true Bc I know it’s true and it’s just true

WINSTONCH [101]2 years ago

5 0

Answer:

true is the answer of the question

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Please can someone solve this physics question with a good explenation.

zimovet [89]

Answer:

The coefficient of dynamic friction is 0.025.

Explanation:

Given:

Initial speed after the push is 'v' as seen in the graph.

Final speed of the stone is 0 m/s as it comes to rest.

Total distance traveled is, $D=29.8\ m$

Total time taken is, $t_{total}=17.5\ s$

Time interval for deceleration is 3.5 to 17.5 s which is for 14 s.

Now, average speed of the stone is given as:

$v_{avg}=\frac{D}{t_{total}}=\frac{29.8}{17.5}=1.703\ m/s$

Now, we know that, average speed can also be expressed as:

$v_{avg}=\frac{v_i+v_f}{2}\\1.703=\frac{v+0}{2}\\v=2\times 1.703=3.41\ m/s$

Now, from the graph, the vertical height of the triangles is, $v=3.41\ m/s$

The deceleration is given as the slope of the line from time 3.5 s to 17.5 s.

Therefore, deceleration is:

$a=\frac{\textrm{Vertical height}}{\textrm{Time interval}}\\a=\frac{v-0}{17.5-3.5}\\a=\frac{3.41}{14}=0.244\ m/s^2$

Frictional force is the net force acting on the stone. Frictional force is given as:

$f=\mu_dN\\Where, \mu_d\rightarrow \textrm{coefficient of dynamic friction}\\N\rightarrow \textrm{Normal force}\\N=mg\\\therefore f=\mu_dmg$

Now, from Newton's second law, net force is equal to the product of mass and acceleration.

Therefore,

$\mu_dmg=ma\\\mu_d=\frac{a}{g}$

Plug in 0.244 for 'a' and 9.8 for 'g'. This gives,

$\mu_d=\frac{a}{g}=\frac{0.244}{9.8}=0.025$

Therefore, the coefficient of dynamic friction is 0.025.

3 0

2 years ago

A dog runs with an initial speed if 7.5m/s on a waxed floor. it slides to a stop in 15 seconds. What is the acceleration

kap26 [50]

Answer:

The answer is -0.5m/s2

Explanation:

I did the test and got it right.

6 0

2 years ago

A book is moved once around the edge of a tabletop with dimensions 1.75 m Ã 2.25 m. If the book ends up at its initial position,

uysha [10]

Explanation:

The dimension of the book is 1.75 m × 2.25 m. If the book ends up at its initial position. The displacement of the book is equal to zero as the object reaches to its initial position.

If it completes its motion in 23 s, t = 23 s

Total displacement of the book is equal to its perimeter. It is given by :

$d=2(1.75+2.25)=8\ m$

The net displacement divided by total time taken is called the average velocity of an object. Here, the displacement is 0. So, average velocity is 0.

The average speed of an object is given by :

$v=\dfrac{d}{t}$

$v=\dfrac{8\ m}{23\ s}$

v = 0.347 m/s

So, the average speed of the book is 0.347 m/s. Hence, this is the required solution.

6 0

2 years ago

Graphs are ____ of relationships.

sashaice [31]

Answer:

Diagrammatic representation

8 0

3 years ago

What is the relationship between mass and acceleration on an object when the force is held constant?

Andreyy89

Answer:

according to newtons second law of motion,

Force = mass * acceleration

The acceleration of the body is directly proportional to the net force acting on the body and inversely proportional to the mass of the body.

I. e mass and acceleration are directly proportional to each other.

8 0

2 years ago