When water dissolves salts, the negative ends of the water molecules are attracted to the negative ions of the salt.

rosijanka [135]

A pulsar, or a pulsing star, is a highly magnetized neutron star that emits a beam of electromagnetic radiation. So they blink when they are rotating because the beam of radiation they emit can only be seen when it is facing the Earth.
Hope this helps.

4 0

2 years ago

A stone is thrown upward from the top of a building at an angle of 30° to the horizontal and with an initial speed of 20 m/s. Th

Hitman42 [59]

Answer:

Explanation:

Given

inclination $\theta =30^{\circ}$

initial speed $u=20\ m/s$

Point of release is 45 m above the ground

Considering stone to be a projectile, so time taken by projectile for its zero vertical displacement is

$t_1=\frac{2u\sin \theta }{g}$

$t_1=\frac{2\times 20\times \sin 30}{10}$

$t_1=2\ s$

Now after completing zero vertical displacement , stone needs to travel another 45 m in downward direction with initial speed u=20\sin 30

$h=u_yt+\frac{1}{2}a_yt^2$

where, $h=height$

$u_y=vertical velocity$

$a_y=vertical acceleration$

$t_0=time$

$45=20\sin 30+\frac{1}{2}(9.8)(t_0)^2$

$t_0^2=\frac{70}{9.8}$

$t_0=2.64\ s$

thus total time time required is $t=t_0+t_1=2.64+2=4.64\ s$

vertical velocity just before hitting

$v_y=\sqrt{u_y^2+2\times a_y\times s}$

$v_y=\sqrt{10^2+2\times 10\times 45}$

$v_y=\sqrt{1000}=31.622\ m/s$

Horizontal velocity $v_x=u\cos 30=17.32\ m/s$

Net velocity Just before hitting $=\sqrt{v_x^2+v_y^2}$

$=\sqrt{(17.32)^2+(31.62)^2}$

$=\sqrt{1299.82}=36.05\ m/s$

7 0

3 years ago

While at soccer practice, Korey ran around the track at 10 meters per second. He had a constant speed and did not change directi

Mariana [72]

Answer:

0m/s²

Explanation:

A body with a constant speed always has a zero acceleration

Hence if Korey ran around the track at 10 meters per second and had a constant speed and did not change directions, then his acceleration will be 0m/s² not considering his initial speed

4 0

2 years ago

The box now rests on a frictionless ramp angled at 15◦ . The mover pulls up on a rope attached to the box to move it up the incl

Nataly [62]

Answer:

F = 84.61 N

Explanation:

As in the figure, since there is no friction so if component of Force applied along the incline is greater than the component of weight along the incline, then the object will move up the incline.

component of Force along the incline = F cos(23° - 15°) = F cos(8°)

component of weight along the incline = 33*g*sin(15°) = 33*9.81*sin(15°)

Equating the above two components of forces will give the minimum Force required.

F cos(8°) = 33*9.81*sin(15°)

F = 33*9.81*sin(15°) / cos(8°) (calculate the value using a scientific calculator)

3 0

3 years ago

An object experiences a 8.9 N force and accelerates 6 m/sec2. What is the object's

Inessa [10]

b stupidrwfs

planation:

3 0

2 years ago