What must be true for any endothermic reaction?

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

True or false: You can calculate a three variable equation knowing only one of the variables.

makvit [3.9K]

Answer:

false

Explanation:

you cant calculate a three variable equation knowing only one of the variables

3 0

3 years ago

If a net force acting on a moving object causes its speed to increase, what

Klio2033 [76]

Answer:

It increases.

Explanation:

If a force acts in the same direction as the object's motion, then the force speeds the object up. Either way, a force will change the velocity of an object. And if the velocity of the object is changed, then the momentum of the object is changed.

7 0

3 years ago

Find the length of an arc with a radius of 6.0m swept across 2.5 radians.

soldier1979 [14.2K]

Hello!

In terms of an arc length, radians is the measurement of an arc length in terms of the original radius. This arc length is 2.5 radians, so we multiply it by our original radius.

2.5(6)=15

Therefore, the arc length is 15 meters.

I hope this helps!

7 0

3 years ago

Cocaine, which is derived from the coca leaf, is grown mostly in Colombia and its neighboring countries while heroin, which is d

nevsk [136]

Answer:

Because of the location, humidity and temperatures.

Explanation:

Coca is grown in humid and very humid subtropical forests, called yungas and

they form the lower floor of the upper Jungle, in the Central Andes, mostly in Peru and Bolivia. The yungas are in contact with the rainforests of the lowlands in Amazonia, where it has been started to expand coca cultivation recently (Dourojeanni, 1988). The optimum altitude is 1000 a 2000 meters (where cocaine content is higher), with optimal annual average precipitation, is 2000 meters mm, but it is grown between 700 and 2000 msnm and with an average annual rainfall of 1000 to 4200 mm.

msnm = meters above sea level

6 0

3 years ago