Which layer contains solid rock and magma

A child pushes a 75 N toy car across the floor. What is the mass of the car?

GaryK [48]

Answer:

7.6 kg

Explanation:

w=75N

w=mg

m=w÷g

m=75÷9.8

m=7.6kg

8 0

3 years ago

One gram of Uranium averages release 1.01 KJ (10^7) of energy. How much mass could be converted to energy to release this much e

frutty [35]

Answer:

The amount of mass that needs to be converted to release that amount of energy is $1.122 X 10^{-7} kg$

Explanation:

From Albert Einstein's Energy equation, we can understand that mass can get converted to energy, using the formula

$E= \Delta mc^{2}$

where $\Delta m$ = change in mass

c = speed of light = $3 \times 10 ^{8}m/s$

Making m the subject of the formula, we can find the change in mass to be

$\Delta m = \frac{E}{c^{2}}= \frac{1.01 \times 10^{3} \times 10^{7}}{(3 \times 10^{8})^{2}}= 1.122 \times 10 ^{-7}kg$

There fore, the amount of mass that needs to be converted to release that amount of energy is 1.122 X 10 ^-7 kg

5 0

3 years ago

What is the net force on a bag pulled down by gravity with a force of 18 newtons and pulled upward by a rope with a force of 18

VARVARA [1.3K]

Answer:

0 N.

Explanation:

Force: This can be defined as the product of mass and the acceleration of the body. The S.I unit of force is Newton (N).

The expression of net force when both force act in the different direction is given as

F' = W-F ........................ Equation 1

Where F' = Net force on the bag, W = gravitational force on the bag, F = Force acting upward on the bag

Given: W = 18 N, F = 18 N.

Substitute into equation 1

F' = 18-18

F' = 0 N.

Hence the net force = 0 N.

4 0

2 years ago

A 57 kg pole vaulter running at 11 m/s vaults over the bar. Her speed when she is above the bar is 1.1 m/s. The acceleration of

kari74 [83]

Answer:

Her altitude as she crosses the bar, h₂ is approximately 6.1 m

Explanation:

The given parameters of the motion of the pole vaulter are;

The mass of the pole vaulter, m = 57 kg

The speed with which the pole vaulter is running, u = 11 m/s

The speed of the pole vaulter when she crosses the bar, v = 1.1 m/s

The acceleration due to gravity, g = 9.8 m/s²

From the total mechanical energy, M.E. equation, we have;

M.E. = P.E. + K.E.

Where;

P.E. = The potential energy of the motion = m·g·h

K.E. = The kinetic energy of the motion = 1/2·m·v²

By the principle of conservation of energy, we have;

The change (loss) in kinetic energy, ΔK.E. = The change (gain) in potential energy, ΔP.E.

ΔK.E. = 1/2·m·(v² - u²)

ΔP.E. = m·g·(h₂ - h₁)

Where;

h₁ = The ground level = 0 m

h₂ = The altitude with which she crosses the bar

∴ 1/2·m·(v² - u²) = m·g·(h₂ - h₁)

(h₂ - h₁) = (v² - u²)/(2·g) = (11² - 1.1²)/(2·9.8) = 6.11173469388

h₂ = 6.11173469388 + h₁ = 6.11173469388 + 0 = 6.11173469388

h₂ = 6.11173469388

Her altitude as she crosses over the bar, h₂ ≈ 6.1 m.

3 0

3 years ago

the large,flat piece of wood within a piano serves the same purpose as(a)a bamboo reed(b)a set of wooden drum sticks(c)a guitar

sammy [17]

The correct answer for the question that is being presented above is this one: "(d) the hollow bix." The large, flat piece of wood within a piano serves the same purpose as <span>(d) the hollow bix. The piece of flat wood will help piano produce a good quality sound.</span>

4 0

3 years ago

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