True or false <br> A ball thrown horizontally.Gravity causes the ball to continue horizontally.

A spherical balloon has a radius of 7.40 m and is filled with helium. Part A How large a cargo can it lift, assuming that the sk

malfutka [58]

Answer:

The mass of the cargo is $M = 188.43 \ kg$

Explanation:

From the question we are told that

The radius of the spherical balloon is $r = 7.40 \ m$

The mass of the balloon is $m = 990\ kg$

The volume of the spherical balloon is mathematically represented as

$V = \frac{4}{3} * \pi r^3$

substituting values

$V = \frac{4}{3} * 3.142 *(7.40)^3$

$V = 1697.6 \ m^3$

The total mass the balloon can lift is mathematically represented as

$m = V (\rho_h - \rho_a)$

where $\rho_h$ is the density of helium with a value of

$\rho_h = 0.179 \ kg /m^3$

and $\rho_a$ is the density of air with a value of

$\rho_ a = 1.29 \ kg / m^3$

substituting values

$m = 1697.6 ( 1.29 - 0.179)$

$m = 1886.0 \ kg$

Now the mass of the cargo is mathematically evaluated as

$M = 1886.0 - 1697.6$

$M = 188.43 \ kg$

5 0

3 years ago

A ceiling fan with 90-cm-diameter blades is turning at 64 rpm . Suppose the fan coasts to a stop 28 s after being turned off. Wh

mixas84 [53]

Answer:

the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.

Explanation:

Given;

diameter of the ceiling fan, d = 90 cm = 0.9 m

angular speed of the fan, ω = 64 rpm

time taken for the fan to stop, t = 28 s

The distance traveled by the ceiling fan when it comes to a stop is calculated as;

$d = vt = \omega r\times t= ( \frac{64 \ rev}{\min} \times \frac{2 \pi \ rad}{rev} \times \frac{1 \min}{60 \ s} \times 0.9 \ m) \times 28 \ s\\\\d = 168.89 \ m$

The speed of the tip of a blade 10 s after the fan is turned off is calculated as;

$v = \frac{d}{t} \\\\v = \frac{168.89}{10} \\\\v = 16.889 \ m/s$

Therefore, the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.

4 0

3 years ago

momentum A proton interacts electrically with a neutral HCl molecule located at the origin. At a certain time t, the proton’s po

arlik [135]

Answer:

$\ m/s$

Explanation:

F = Force =

m = Mass of proton = $1.7\times 10^{-27\ kg$

t = Time taken = $2\times 10^{-14}\ s$

Acceleration is given by

$a=\dfrac{F}{m}\\\Rightarrow a=\dfrac{}{1.7\times 10^{-27}}\\\Rightarrow a=\ m/s^2$

$v=u+at\\\Rightarrow v=+\times 2\times 10^{-14}\\\Rightarrow v=+\times 2\times 10^{-14}\\\Rightarrow v=+\\\Rightarrow v=\ m/s$

The velocity of the proton is $\ m/s$

6 0

3 years ago

A block, M1=10kg, slides down a smooth, curved incline of height 5m. It collides elastically with another block, M2=5kg, which i

erma4kov [3.2K]

Answer:

2.86 m

Explanation:

Given:

M₁ = 10 kg

M₂ = 5 kg

$\mu_k$ = 0.5

height, h = 5 m

distance traveled, s = 2 m

spring constant, k = 250 N/m

now,

the initial velocity of the first block as it approaches the second block

u₁ = √(2 × g × h)

or

u₁ = √(2 × 9.8 × 5)

or

u₁ = 9.89 m/s

let the velocity of second ball be v₂

now from the conservation of momentum, we have

M₁ × u₁ = M₂ × v₂

on substituting the values, we get

10 × 9.89 = 5 × v₂

or

v₂ = 19.79 m/s

now,

let the velocity of mass 2 when it reaches the spring be v₃

from the work energy theorem, we have

Work done by the friction force = change in kinetic energy of the mass 2

or

$0.5\times5\times9.8\times2 = \frac{1}{2}\times5\times( v_3^2-19.79^2)$

or

v₃ = 20.27 m/s

now, let the spring is compressed by the distance 'x'

therefore, from the conservation of energy

we have

Energy of the spring = Kinetic energy of the mass 2

or

$\frac{1}{2}kx^2=\frac{1}{2}mv_3^2$

on substituting the values, we get

$\frac{1}{2}\times250\times x^2=\frac{1}{2}\times5\times20.27^2$

or

x = 2.86 m

8 0

3 years ago

Explain the role of energy in changes <br> of state.

slava [35]

A liquid requires enthalpy of vaporization to transform into vapor or gas at its boiling point. Here the element absorbs heat from surroundings or heat source.

This energy is used in breaking the forces of attraction among the atoms and molecules of the element. The molecules get separated to higher distances. The energy is converted in to the kinetic energy of the molecules in gaseous form and into the internal energy in terms of the temperature of the gas.

3 0

3 years ago

True or false A ball thrown horizontally.Gravity causes the ball to continue horizontally.