Which of the following statements are true about magnets?

chris and molly wins $2400 in a competition they share the money in the ratio2:3 how much money do they each receive ?

nlexa [21]

Answer:

chris gets 960 and molly gets 1440

Explanation:

add the ratio up and divide

2+3=5

2400/5=480

480x2=960

480x3=1440

960+1440= 2400

5 0

2 years ago

What are 3 criteria for acceleration?

Temka [501]

I don't think you mean 'criteria'. I think you mean three occurrences or
observations that indicate the presence of acceleration.

They are:

-- an object is speeding up
-- an object is slowing down
-- the direction of an object's motion is changing .

Any one of these changes is acceleration.

There's a single term that covers them all. It is "change in velocity".

3 0

3 years ago

Assume we’re able to travel to your planet and decide to take some fireworks with us to celebrate our journey.

julia-pushkina [17]

Answer:

The horizontal distance covered by the firework will be $\frac{1876.8}{g}$

Explanation:

Let acceleration due to gravity on the planet be g, initial velocity of the firework be u and angle made with the horizontal be ∅.

writing equation of motion in vertical direction:

$v_{y}=u_{y}+(-g) t$

$u_{y}= u\sin \phi$

and $v_{y}=0$

therefore $\frac{u\sin \phi }{g} =t$

writing equation of motion in horizontal direction:

$s_{x}=u_{x}t$

$u_{x} = u\cos \phi$

therefore the equation becomes $s_{x}=\frac{u^{2} \sin \phi \cos \phi}{g}$

therefore horizontal distance traveled = $\frac{u^{2}\sin 2\alpha \phi }{2g}=\frac{1876.8}{g}\frac{m}{s}$

5 0

2 years ago

A horizontal net force F is exerted on an object at rest. The object starts at x=0 m and has a speed of 4.0 m/s after moving 4.0

Alex_Xolod [135]

Explanation:

The solution is be found in the attachment.

8 0

2 years ago

a mass of 0.75 kg is attached to a spring and placed on a horizontal surface. the spring has a spring constant of 180 N/m, and t

Artemon [7]

Answer:

6.57 m/s

Explanation:

First use Hook's Law to determine the F the compressed spring acts on the mass. Hook's Law F=kx; F=force, k=stiffnes of spring (or spring constant), x=displacement

F=kx; F=180(.3) = 54 N

Next from Newton's second law find the acceleration of the mass.

Newton's .2nd law F=ma; a=F/m ; a=54/.75 = 72m/s²

Now use the kinematic equation for velocity (or speed)

v₂²= v₀² + 2a(x₂-x₀); v₂=final velocity; v₀=initial velocity; a=acceleration; x₂=final displacement; x₀=initial displacment.

v₀=0, since the mass is at rest before we release it

a=72 m/s² (from above)

x₀=0 as the start position already compressed

x₂=0.3m (this puts the spring back to it's natural length)

v₂²= 0 + 2(72)(0.3) = 43.2 m²/s²

v₂= $\sqrt{43.2)\\$ = 6.57 m/s

5 0

3 years ago