All categories

3 years ago

A ball is dropped from a height of 20 meters. At what height does the ball have a velocity of 10 meters/second?

Physics

1 answer:

borishaifa [10]3 years ago

6 0

Answer:B

Explanation:

Initial velocity, u=0m/s

Distance,s=20m

a=+g=9.8m/s*s

Using v*v=u*u+2gs

v*v=0+2*9.8*20

v*v=392

v=19.8

When s=20m, v = 19.8m/s

Therefore when v = 10m/s, s= 10*20/19.8

s =10.1m

You might be interested in

Choose the correct statement regarding energy production in the interior of a star and energy production in a power plant. A sta

sergij07 [2.7K]

Answer:

A star uses fusion as an energy source by building larger atoms from smaller atoms.

Explanation:

Nuclear fission and fusion are two processes at which an atomic nucleus is changed to produce energy. Fission is the process splitting heavy atomic into lighter atomic nuclei.

So, fusion is the combination of smaller atoms to form larger atoms and star uses this as source of energy.

Fusion is the process at which light atomic nuclei are merged or fused together to form heavier nuclei.

The energy source for all stars is nuclear fusion. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom.

8 0

4 years ago

Read 2 more answers

2. Sally put her mug of coffee on the table. The mug has a mass of 1 kg. if the pressure

egoroff_w [7]

We have,

The mass of sally's mug is 1 kg
The pressure appliedby the mug is 1100 pascal.

We know that,

Pressure = Force/Area

As, we already have the value of pressure, let's calculate that of force now;

F = ma
F = 1 × 9.8 { Acceleration due to gravity, let's round off it to 10}
F = 10 N

Just put all the values in the formula now;

P = F/A
1100 = 10 / A
1100/10 = A
110 m² = A

As, it is already mention that we need to find the radius of the mug, it is obviously a circular base.

We know that,

Surface area = Circumference

So, let's solve it;

Circumference = 2πr
110 = 2 × 22/7 × r
110 × 7/2 × 22 = r
5 × 7 = r
35 cm = r

Thus, the radius of the circle is 35 cm.

7 0

3 years ago

A truck going 15 kmôŹ°€h has a head-on collision with a small car going 30 kmôŹ°€h. Which statement best describes the situation

zlopas [31]

1. e) None of the above is necessarily true.

2.d) Without knowing the mass of the boat and the sack, we cannot tell.

5 0

3 years ago

A wire 40cm long and of diameter 0.60mm has a resistance of 1.5 ohm what is the resistivity of the material of which it is made

zavuch27 [327]

Answer:

The resistivity of the wire is $1.05\times 10^{-6}\ \Omega-m$

Explanation:

We have,

Length of a wire is 40 cm or 0.4 m

Diameter of a wire is 0.60 mm

Radius is 0.3 mm or 0.0003 m

Resistance of a wire is 1.5 ohm

Now we need to find the resistivity of the material of which it is made. The resistance of a wire in terms of its resistance, length and area is given by :

$R=\rho \dfrac{l}{A}$

$\rho$ = resistivity

$\rho=R \dfrac{\pi r^2}{l}\\\\\rho=1.5\times \dfrac{3.14\times (0.0003 )^2}{0.4}\\\\\rho=1.05\times 10^{-6}\ \Omega-m$

So, the resistivity of the wire is $1.05\times 10^{-6}\ \Omega-m$ .

3 0

3 years ago

The regions of the Moon that are of higher elevation are known as the __________. These regions have a high albedo and display a

REY [17]

Answer:

lunar highlands

Explanation:

Seeing the moon from the earth we can see that some parts are more illuminated than others, these different regions of the moon have been assigned a name , and have different properties.

The brightest parts are called lunar highlands, because they are at a higher elevation than the darkest parts, called lunar marias.

The lunar highlands are seen from the earth a whiter color than the rest of the moon due to its altitude.

4 0

4 years ago