I need help with all of these questions

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

3 years ago

What does Newton's first law of motion state? (3 points) a Every action has an equal and opposite reaction. b A body at rest wil

kirza4 [7]

Answer:

B) A body at rest will stay at rest

Explanation:

A body in motion will stay in motion unless acted on by another force.

3 0

2 years ago

Read 2 more answers

According to Charles's law, for a fixed quantity of gas at constant pressure, which of the given quantities is constant? Accordi

Naddik [55]

Charles's law is also known as the law of volumes explained the relation between the volume of gas and its temperature.

Charles's law states that: " At constant pressure, the volume of a certain mass of gas is directly proportional to its temperature in kelvin".
This means that:
V = T*constant
V/T = constant

Based on this, the correct choice is:
a) V/T

7 0

3 years ago

Read 2 more answers

An object 7 cm tall is placed at different locations in front of a concave mirror whose radius of curvature is 64 cm. Determine

cestrela7 [59]

The Asante was fhhbbd

3 0

3 years ago

Measuring the diameter of a specific object might include which pair of SI units

VLD [36.1K]

Well, the diameter of a circle is simply a length, so your measurement will have units of length. We just have to find an answer that has only units of length.

A). gram, second . . . mass and time. That can't be it.

B). kilogram, ampere . . . mass and current. That can't be it.

C). centimeter, meter . . . both lengths. This one is looking good.

D). candela, mole . . . light intensity and some chemical thing. That can't be it.

So it can't be anything else on this list but C .

8 0

3 years ago