Answer:
Its acceleration is positive
Explanation:
As the car is moving in the negative x-direction than after applying brake then there will be a decrease in the acceleration but in the opposite direction.
As decreasing acceleration consider to be negative but the car is moving in negative direction which means increasing acceleration is negative by sign convention but by applying brake acceleration decrease but in opposite direction than it will give positive value of acceleration.
The minimum initial speed of the dart so that the combination makes a complete circular loop after the collision is 58.5 m/s.
<h3>Minimum speed for the object not fall out of the circle</h3>
The minimum speed if given by tension in the wire;
T + mg = ma
T + mg = m(v²)/R
tension must be zero for the object not fall
0 + mg = mv²/R
v = √(Rg)
<h3>Final speed of the two mass after collision</h3>
Use the principle of conservation of energy
K.Ef = K.Ei + P.E
¹/₂mvf² = ¹/₂mv² + mg(2R)
¹/₂vf² = ¹/₂v² + g(2R)
¹/₂vf² = ¹/₂(Rg) + g(2R)
vf² = Rg + 4Rg
vf² = 5Rg
vf = √(5Rg)
vf = √(5 x 2.8 x 9.8)
vf = 11.7 m/s
<h3>Initial speed of the dart</h3>
Apply principle of conservation of linear momentum for inelastic collision;
5v = vf(20 + 5)
5v = 11.7(25)
5v = 292.5
v = 58.5 m/s
Learn more about linear momentum here: brainly.com/question/7538238
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Note that
1 J = 0.239 cal
By definition,
Work = Force x Distance
Therefore work done is
W = (1 N)*(2000 m) = 2000 J
In calories,
W = (2000 J)*(0.239 cal/J) = 478 cal
Answer: 478 calories
The correct answer is:
<span>Point charges must be in a vacuum.
In fact, the usual form for of the Coulomb's law is:
</span>
<span>where
</span>
is the permittivity of free space
<span>q1 and q2 are the two charges
q is the separation between the two charges
However, this formula is valid only if the charges are in vacuum. If they are in a material medium, the law is modified as follows:
</span>
where
is the relative permittivity, which takes into account the dielectric effects of the material.
Answer:
Correct answer: Ek = I² / 2 · m
Explanation:
The formula by which kinetic energy is calculated is:
Ek = m V² / 2
The formula by which momentum i prefer the name impulse is calculated is:
I = m V
We will transform the formula for kinetic energy on the next way:
Ek = m V² / 2 we will multiply numerator and denominator with m and get:
Ek = m² V² / 2 m = (m v)² / 2 m = I² / 2 m
Ek = I² / 2 m
God is with you!!!