I need some help?

A 2.55 kg block starts from rest on a rough inclined plane that makes an angle of 60 degree with the horizontal. the coefficient

lorasvet [3.4K]

Answer:

Change in mechanical energy = work done by friction

so it is equal to

$W = -8.16 J$

Explanation:

As we know that change in mechanical energy must be equal to the work done by non conservative forces only

So here when block moves down the inclined plane then the work done by friction force is given as

$W = F.d$

here we have

$F = \mu F_n$

here we know that

$F_n = mg cos\theta$

so we have

$F_n = 2.55(9.81)(cos60)$

$F_n = 12.5 N$

Now the friction force on the block is given as

$F_f = \mu F_n$

$F_f = 0.25 \times 12.5$

$F_f = 3.13 N$

now work done by the friction is given as

$W = -(3.13)(2.61)$

$W = -8.16 J$

7 0

4 years ago

27. The traffic officer issued violation tickets to traffic

Evgen [1.6K]

Answer:

27: 85

28:75%

Explanation:

27:68=80

?=100 hence (68×100)÷80

=85

28:18/24× 100

 =75%

3 0

4 years ago

Each of the following statements is arguably true of thermometers. Which of them is most helpful to keep in mind if you are cond

Lera25 [3.4K]

Answer:

The temperature reported by a thermometer is never precisely the same as its surroundings

Explanation:

In this experiment to determine the specific heat of a material the theory explains that when a heat interchange takes place between two bodies that were having different temperatures at the start, the quantity of heat the warmer body looses is equal to that gained by the cooler body to reach the equilibrium temperature. This is true only if no heat is lost or gained from the surrounding. If heat is gained or lost from the surrounding environment, the temperature readings by the thermometer will be incorrect. The experimenter should therefore keep in mind that for accurate results, the temperature recorded by the thermometer is similar to that of the surrounding at the start of the experiment and if it differs then note that there is either heat gained or lost to the environment.

3 0

3 years ago

You are asked to calculate how long a new battery will last on a flashlight when the flashlight is turned on. how long should yo

valina [46]

Answer:

Depends on the capacity of battery. Mostly our phones flashlight can be used up to 8 to 10hrs continuosly

Explanation:

Capacity of the battery is level to which battery is charged, & amount of current drawn by the flashlight, you can calculate the answer yourself if u know the capacity of that light.

Moreover you can calculate this by using equation,

E =Pt

So, for time

t=E/P

Batteries are rated in Amp hours, like 10 amp hours will supply us 1 amp for 10 hours

2 amps will give us 5 hours

to learn more about lasting of flashlight,

brainly.com/question/13869629?referrer=searchResults

#SPJ4

5 0

2 years ago

An automobile with a mass of 1250 kg accelerates at a rate of 4 m/sec2 in the forward direction. What is the net force acting on