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1 year ago

starting from rest a skateboarder accelerates at a rate of 2 [m/s 2] for 2 [s]. what is their speed afterwards?

Physics

1 answer:

N76 [4]1 year ago

7 0

Answer:

sorry I don't know I am too bad a t this coz I am only at class 7

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PLZ HELP ME i don’t get this

Scorpion4ik [409]

Explanation:

(i) Height of tree, h = 4 m

Mass of Ninja, m = 30 kg

The gravitational potential energy on the top branch of the tree is given by :

$P=mgh$

g is acceleration due to gravity

$P=30\ kg\times 9.8\ m/s^2\times 4\ m\\\\P=1176\ J$

(ii) If he were at a height of 2 meters from the ground, its potential energy will be :

$P=mgh$

g is acceleration due to gravity

$P=30\ kg\times 9.8\ m/s^2\times 2\ m\\\\P=588\ J$

Therefore, this is the required explanation.

4 0

2 years ago

On a part-time job, you are asked to bring a cylindrical iron rod of density 7800 kg/m3 , length 92.6 cm and diameter 2.95 cm fr

slavikrds [6]

Answer:

48.4293354946 N

Yes

Explanation:

d = Diameter of rod = 2.95 cm

h = Length of rod = 92.6 cm

$\rho$ = Density of rod = 7800 kg/m³

g = Acceleration due to gravity = 9.81 m/s²

Volume of rod

$V=\dfrac{1}{4}\pi d^2h\\\Rightarrow V=\dfrac{1}{4}\times \pi\times (2.95\times 10^{-2})^2\times 92.6\times 10^{-2}$

Mass is given by

$m=\rho V\\\Rightarrow m=7800\times \dfrac{1}{4}\times \pi\times (2.95\times 10^{-2})^2\times 92.6\times 10^{-2}\\\Rightarrow m=4.93673144695\ kg$

Weight is given by

$W=mg\\\Rightarrow W=4.93673144695\times 9.81\\\Rightarrow W=48.4293354946\ N$

The weight of the rod is 48.4293354946 N

The mass of the rod is 4.93673144695 kg which is light. So, I will be able to carry the rod without a cart.

7 0

2 years ago

Sound is an example of ?

wlad13 [49]

Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

8 0

2 years ago

Read 2 more answers

O((>ω< ))oo((>ω< ))oo((>ω< ))oo((>ω< ))oo((>ω< ))o

Paladinen [302]

Answer:

(•_•)

Explanation:

7 0

2 years ago

Which of the following statements is/are true?Check all that apply.a. A conservative force permits a two-way conversion between

Eddi Din [679]

Answer:

a). A conservative force permits a two-way conversion between kinetic and potential energies.

TRUE

Because there is no energy loss in presence of conservative forces so energy conversion in two ways are possible.

b). A potential energy function can be specified for a conservative force.

TRUE

negative gradient of potential energy is equal to conservative force

$F = -\frac{dU}{dr}$

c). A non-conservative force permits a two-way conversion between kinetic and potential energies.

FALSE

here energy is lost against non-conservative forces

d). The work done by a conservative force depends on the path taken.

FALSE

work done by conservative force is independent of path

e). The work done by a non-conservative force depends on the path taken.

TRUE

work done by non conservative forces depends on path.

f). A potential energy function can be specified for a non-conservative force.

FALSE

It is not defined for non conservative forces

3 0

2 years ago