Trick question (really easy) just for fun! If u get this right u get brainliest!

A block is projected up a frictionless inclined plane with initial speed v0 = 7.14 m/s. The angle of incline is θ = 36.5°. (a) H

Wewaii [24]

Answer:

$(a)x=4.37m\\\\(b)t=1.225s\\\\(c) v_{f}=7.14m/s$

Explanation:

Given data

$v_{o}=7.14m/s\\\alpha =36.5^o$

For Part (a)

Starting with the -ve acceleration of the body (opposite to the gravitational force)

$a=-gSin\alpha \\a=-(9.8m/s^2)Sin(36.5)\\a=-5.83m/s^2$

Using equation of motion

$v_{f}^2=v_{o}^2+2ax\\(0m/s)^2=(7.14m/s)^2+2(-5.83m/s^2)x\\-(7.14m/s)^2=2(-5.83m/s^2)x\\x=\frac{-(7.14m/s)^2}{2(-5.83m/s^2}\\ x=4.37m$

For Part (b)

Using the result in Part (a) we can substitute in other equation of motion to get time t:

$x=\frac{1}{2}vt\\ 4.37m=\frac{1}{2}(7.14m/s)t\\ (7.14m/s)t=2*(4.37)\\t=8.744/7.14\\t=1.225s$

For Part (c)

At state 2 where vo=0m/s and the acceleration is positive (same direction as the gravitational force)

$a=gSin\alpha \\a=(9.8m/s^2)Sin(36.5)\\a=5.83m/s^2\\\\\\v_{f}^2=v_{o}^2+2ax\\v_{f}^2=(0m/s)^2+2(5.83m/s^2)(4.37m)\\v_{f}^2=50.95\\v_{f}=\sqrt{50.95}\\ v_{f}=7.14m/s$

4 0

3 years ago

A 20 kg crate of books is at rest on a table. what is the normal force on the books?

Umnica [9.8K]

The weight of 20 kg is

(mass) x (gravity) =

(20 x 9.8) = 196 newtons, downward.

There must be a force of 196 newtons upward on the mass.
Otherwise the mass is accelerating either up or down.

4 0

3 years ago

What is Pressure ? Explain well

Andreyy89

Hi Pupil Here's Your Answer ::

➡➡➡➡➡➡➡➡➡➡➡➡➡

Pressure is defined as the force acting perpendicular on an unit area of the surface.

OR

The thrust per unit area is called Pressure.

let us see, on what factors the pressure depends?

Take a pin having a pointed end and a nail having blunt end. Press then against a cardboard by applying the same force. We find that the pin penetrates deep into the cardboard then the nail. In this case, force acting on two points of the cardboard is same but the area under the tip of the Pin is less than under the tip of the nail.

The effect of the forces of the scene magnitudes on the different area is different.

Conclusions : Pressure acting on the surface is inversely proportional to the area of the surface on which force acts.

⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅⬅

Hope this helps

4 0

3 years ago

Suppose the experiment was conducted in the same manner, but the axle was now off center of the solid disk. Would you expect the

san4es73 [151]

Answer:

Explanation:

If Ig be moment of inertia about an axis through centre of mass and I be moment of inertia through any other axis parallel to earlier axis , then according to theory of parallel axis ,

I = Ig + Md²

where M is mass of the body and d is distance between two parallel axis.

So I is greater than Ig.

4 0

3 years ago

You are trying to determine the specific gravity of a solid object that floats in water. If m is the mass of your object, mS is

Alisiya [41]

Answer:

Specific Gravity = m/[m(s)-m(os)]

Explanation:

Specific gravity, also called relative density, is the ratio of the density of a substance to the density of a reference substance. By this definition we need to find out the ratio of density of the object of mass m to the density of the surrounding liquid.

m = mass of the object

Weight in air

W (air) = mg, where g is the gravitational acceleration

Weight with submerged with only one mass

m(s)g + Fb = mg + m(b)g, consider this to be equation 1

where Fb is the buoyancy force

Weight with submerged with both masses

m(os)g + Fb’ = mg + m(b)g, consider this to be equation 2

equation 1 – equation 2 would give us

m(s)g – m(os)g = Fb’ – Fb

where Fb = D x V x g, where D is the density of the liquid the object is submerged in, g is the force of gravity and V is the submerged volume of the object

m(s)g – m(os)g = D(l) x V x g

m(s) – m(os) = D(l) x V

we know that Mass = Density x V, which in our case would be, D(b) x V, which also means

V = Mass/D(b), where D(b) is the density of the mass

Substituting V into the above equation we get

m(s) – m(os) = [D(l) x m)/ D(b)]

Rearranging to get the ratio of density of object to the density of liquid

D(b)/D(l) = m/[m(s)-m(os)], where D(b)/D(l) denotes the specific gravity

8 0

3 years ago