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2 years ago

If a body of mass 2 kg is moving with a velocity of 30 m/s, then

Physics

1 answer:

Svetllana [295]2 years ago

7 0

Answer:

d. 60

Explanation:

If a body of mass 2 kg is moving with a velocity of 30 m/s, then

on doubling its velocity the momentum becomes

a 30 kgm/s

b 90 kgm/s

C 120 kgm/s

d 60 kgm/s

HALPLPLPPLL

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Explain why stellar parallax cannot be used to measure the distance to other galaxies.

Phoenix [80]

Answer:

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They are so distant that the parallax is too small to be measured since parallax varies

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We can figure out their luminosities from their periods of variation. Then if we measure

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2 years ago

Identify the phyla of the organisms on the basis of following distinct characteristics:

MrRissso [65]

Answer:

Phylum Annelida commonly referred as segmented worms possess long , cylindrical and segmented body .

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2 years ago

Water is being boiled in an open kettle that has a 0.52-cm-thick circular aluminum bottom with a radius of 12.0 cm. If the water

tangare [24]

Answer:

$T_b=107.3784\ ^{\circ}C$

Explanation:

Given:

thickness of the base of the kettle, $dx=0.52\ cm=5.2\times 10^{-3}\ m$

radius of the base of the kettle, $r=0.12\ m$

temperature of the top surface of the kettle base, $T_t=100^{\circ}C$

rate of heat transfer through the kettle to boil water, $\dot Q=0.409\ kg.min^{-1}$

We have the latent heat vaporization of water, $L=2260\times 10^3\ J.kg^{-1}$

and thermal conductivity of aluminium, $k=240\ W.m^{-1}.K^{-1}$

$\dot Q=\frac{0.409\times 2260000}{60}$

$\dot Q=15405.67\ W$

<u>From the Fourier's law of conduction we have:</u>

$\dot Q=k.A.\frac{dT}{dx}$

$\dot Q=k\times \pi.r^2\times \frac{T_b-T_t}{5.2\times 10^{-3}}$

where:

$A=$ area of the surface through which conduction occurs

$T_b=$ temperature of the bottom surface

$15405.67=240\times \pi\times 0.12^2\times \frac{T_b-100}{5.2\times 10^{-3}}$

$T_b=107.3784\ ^{\circ}C$ is the temperature of the bottom of the base surface of the kettle.

6 0

2 years ago

How much force is needed to accelerate an object of mass 90 kg at a rate of 1.2 m/s2

soldier1979 [14.2K]

∑F = ma = (90 kg)(1.2 m/s²) = 108 N = 100 N (1 significant digit)

3 0

2 years ago

Read 2 more answers

A motorbike reaches a speed of 20 m/s over 60m, whilst

Fynjy0 [20]

Initial speed = 2√10 m/s

<h3>Further explanation </h3>

Linear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration

An equation of uniformly accelerated motion

V = vo + at

Vt² = vo² + 2a (x-xo)

x = distance on t

vo / vi = initial speed

vt / vf = speed on t / final speed

a = acceleration

vf=20 m/s

d = 60 m

a = 3 m/s²

$\tt vf^2=vi^2+2.ad\\\\20^2=vi^2+2\times 3\times 60\\\\400=vi^2+360\\\\40=vi^2\\\\vi=\sqrt{40}=2\sqrt{10}~m/s$

7 0

2 years ago