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4 years ago

A 8.1 kg object initially at rest is pushed down a 15.0 m tall hill. What is the speed of the object at the bottom of the hill?

Physics

1 answer:

topjm [15]4 years ago

8 0

Answer:

The velocity of the object at the bottom is, v = 17.15 m/s

Explanation:

Given data,

The initial velocity of the object, u = 0

The height of the hill, h = 15 m

Let 'S' be the distance of the slope of the hill and 'Ф' be the slope of the hill formed with the ground.

The acceleration due to gravity component along the slope is given by,

a = g Sin Ф

The distance of the slope since height 'h' of the hill is given,

s = h / Sin Ф

Using the III equation of motion,

v² = 2 as (∵ u = 0)

v² = 2 x g Sin Ф x h / Sin Ф

= 2 gh

Therefore,

Substituting the given values,

v = √(2x9.8x15)

= 17.15 m/s

Hence, the velocity of the object at the bottom is, v = 17.15 m/s

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Oil having a density of 930 kg/m^3 floats on

Zolol [24]

Answer:

0.0268 m

Explanation:

Draw a free body diagram of the block. There are three forces: weight force mg pulling down, buoyancy of the oil B₁ pushing up, and buoyancy of the water B₂ pushing up.

Sum of forces in the y direction:

∑F = ma

B₁ + B₂ − mg = 0

ρ₁V₁g + ρ₂V₂g − mg = 0

ρ₁V₁ + ρ₂V₂ = m

ρ₁V₁ + ρ₂V₂ = ρV

ρ₁Ah₁ + ρ₂Ah₂ = ρAh

ρ₁h₁ + ρ₂h₂ = ρh

(930 kg/m³)h₁ + (1000 kg/m³)h₂ = (968 kg/m³) (4.93 cm)

Since the block is fully submerged, h₁ + h₂ = 4.93 cm.

(930 kg/m³) (4.93 cm − h₂) + (1000 kg/m³)h₂ = (968 kg/m³) (4.93 cm)

h₂ = 2.68 cm

h₂ = 0.0268 m

4 0

3 years ago

A 5.0 g coin is placed 15 cm from the center of a turntable. The coin has static and kinetic coefficients of friction with the t

Kaylis [27]

Answer:

Angular speed will reach 6.833rad/s before the coin starts slipping

Explanation:

There is no question but I'll asume the common one: Calculate the speed of the turntable before the coin starts slipping.

With a sum of forces:

$Ff = m*a$

$Ff=m*V^2/R$

At this point, friction force is maximum, so:

$\mu*N=m*V^2/R$

$\mu*m*g=m*V^2/R$

Solving for V:

$V=\sqrt{\mu*g*R}$

V=1.025 m/s

The angular speed of the turntable will be:

ω = V/R = 6.833 rad/s This is the maximum speed it can reach before the coin starts slipping.

7 0

3 years ago

A normal blood pressure reading is less than 120/80 where both numbers are gauge pressures measured in millimeters of mercury (m

KIM [24]

The pressure value is given by the equation,

$P= \rho gh$

Where,

$\rho$ represents the density of the liquid

g= gravity

h= Heigth

A) For the measurement of the guage pressure we have the data data,

$\rho_{mercury} = 13.6*10^3kg/m^3$

$h=0.0930m$

$g=9.8m/s^2$

Replacing we get,

$P_g=\rho_{mercury}gh$

$[tex]P_g = (13.6*10^3)(9.8)(0.0930)$ P_g = 12395Pa[/tex]

In order to find the Absolute pressure, we perform a sum between the atmospheric pressure and that of the Gauge,

B) The atmospheric pressure at sea level is 101325Pa, assuming ideal conditions, we will take this pressure for our calculation, so

$P_T = P_a+P_g\\P_T = 101325Pa+12395Pa\\P_T = 113720Pa\\P_T = 113.7kPa$

6 0

3 years ago

Which element most likely has a shiny luster

ruslelena [56]

Answer:

Rhodium. This extremely rare, valuable and silvery-colored metal is commonly used for its reflective properties. ...

Platinum.

Gold.

Iridium.

Osmium.

Palladium.

Rhenium

Explanation:

4 0

3 years ago

Read 2 more answers

Would a rougher or smoother object absorb thermal energy faster? Why? Give an example.

Nuetrik [128]

Smoother because it will increase energy and when the energy increases it’ll create heat also . Example: A car racing on a smooth road it’ll go faster than a Car speeding on a bumpy and rough road , Hope that helps .

5 0

4 years ago