All categories

3 years ago

Plz help the ones i looked up are wrong

1 answer:

tatiyna3 years ago

3 0

Answer:

As a girl pushes a bike up a hill, the kinetic energy of the bike is increasing.

Explanation:
As a bike goes up hill it’s easy to determine wether it’s decreasing or increasing depending on which way it goes downhill or uphill!

You might be interested in

Estimate the speed of the water free surface and the time required to fill with water a cone-shaped container 1.5 m high and 1.5

Zolol [24]

Answer:

speed of water is 0.0007138m/s

Explanation:

From the law of conservation of mass

Rate of mass accumulation inside vessel = mass flow in - mass flow out

so, dm/dt = mass flow in - mass flow out

taking p as density

$d \frac{dQ}{dt} = pq_i_n$

where,

q(in) is the volume flow rate coming in

Q = is the volume of liquid inside tank at any time

But,

dQ = Adh

where ,

A = area of liquid surface at time t

h = height from bottom at time t

A = πr²

r is the radius of liquid surface

$r = (1.5/2) \div 1.5$ $h = \frac{h}{2}$

Hence,

$\pi( \frac{h}{2} )^2\frac{dh}{dt} =q_i_n$

$\frac{dh}{dt} = \frac{q_i_n}{\pi (\frac{h}{2})^2 } =\frac{4q_i_n}{\pi h^2}$

so, the speed of water surface at height h

$v = \frac{dh}{dt} =\frac{4q_i_n}{\pi h^2}$

where,

$q_i_n$ is 75.7 L/min = 0.0757m³/min

h = 1.5m

so,

$v = \frac{4 \times 0.0757}{\pi \times 1.5^2} \\\\v = 0.04283m/min$

v = 0.04283 /60

v = 0.0007138m/s

Hence, speed of water is 0.0007138m/s

5 0

3 years ago

An experimental 1500-kg car travels at a constant speed of 22 m/s around a circular test track that is 80 m across. What is the

stepladder [879]

Answer:

363000 J or 363 kJ

Explanation:

Because the car is not rotating, it has no rotational kinetic energy. Its kinetic energy is then simply

$\frac{1}{2} mv^2 = \frac{1}{2}\times1500\times22^2 = 363000 \text{ J}$

8 0

4 years ago

If the magnitude of a positive charge is tripled, what is the ratio of the original value of the electric field at a point to th

dybincka [34]

Answer:

Here is the complete question.

If the magnitude of a positive charge is tripled, what is the ratio of the original value of the electric field at a point to the new value of the electric field at that same point.

a) 1:2

b) 1:3

c)1:6

d)1:9

b) 1:3 is the correct option.

Explanation:

7 0

3 years ago

The center of a moon of mass m is a distance D from the center of a planet of mass M. At some distance x from the center of the

seraphim [82]

Answer:

$x=\dfrac{D}{1+\sqrt{\dfrac{m}{M}}}$

Explanation:

Mass of moon = m

Mass of planet =M

We know that gravitational force given as

$F=G\dfrac{m_1m_2}{d^2}$

$F'=G\dfrac{m'M}{x^2}$

$F=G\dfrac{m'm}{(D-x)^2}$

Given that force is zero so

F=F'

$G\dfrac{m'm}{(D-x)^2}=G\dfrac{m'M}{x^2}$

$\dfrac{m}{(D-x)^2}=\dfrac{M}{x^2}$

$\dfrac{x}{D-x}=\sqrt{\dfrac{M}{m}}$

$\dfrac{D-x}{x}=\sqrt{\dfrac{m}{M}}$

$x=\dfrac{D}{1+\sqrt{\dfrac{m}{M}}}$

6 0

3 years ago

The ionization energy of an atom is the energy required to remove an electron from the atom. In the Bohr model, the ionization e

Aleksandr-060686 [28]

The question is incomplete, the complete question is;

The ionization energy of an atom is the energy required to remove an electron from the atom. In the Bohr model, the ionization energy equals the energy difference between the lowest energy level n = 1 , In which the electron is closest to the nucleus, and the energy level n oo, which has an infinite radius. Compared to the ionization energy of hydrogen, the energy required to remove the electron from singly ionized helium is O two times greater. O four times greater. eight times greater. O one-half as great. O one-fourth as great.

Answer:

four times greater

Explanation:

For a hydrogen atom, an ionization energy of 13.6 electron volts is required to eject its single electron from the lowest energy level all the way out of the atom.

The helium ground state contains only two 1s electrons. When one of these is removed, He^+ looks quite similar to H^+.

The energy required to remove the remaining helium electron should be; 4×(13.6eV)=54.4eV since the energy depends on the square of the nuclear charge.

7 0

3 years ago