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3 years ago

How do I figure out if the acceleration is negative, positive or zero ?

Physics

1 answer:

Licemer1 [7]3 years ago

8 0

Use acceleration = Final Velocity - Initial Velocity. So for the first one:
1.6m/s - 3.6m/s = -2.6m/s. This means the velocity changed by a negative amount so the acceleration is negative.

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Two planes leave wichita at noon. one plane flies east 30 mi/h faster than the other plane, which is flying west. at what time w

scoundrel [369]

You have to take note of the individual directions of the plane. Since one is heading east, and the other is heading west, the planes are heading at opposite directions. So, it means that their distance between each other would be equal to 1,200 miles which accounts for the sum of their individual distances. The equation is as follows:

Total Distance = Distance of slower plane + Distance of faster plane
1,200 miles = st + (30+s)(t)
where
s is the speed of the slower plane and t is the time. Since both are not given, the final answer would just be in terms of s.
1,200 = t(s + 30 + s)
t = 1200/(30+2s)
t = 600/(15+s)

4 0

3 years ago

a cylinder has a radius of 2.1cm and a length of 8.8cm .total charge 6.1 x 10^-7C is distributed uniformly throughout. the volum

7nadin3 [17]

The answer for the following problem is explained below.

Therefore the volume charge density of a substance (ρ) is 0.04 × $10^{-1}$ C.

Explanation:

Given:

radius (r) =2.1 cm = 2.1 × $10^{-2}$ m

height (h) =8.8 cm = 8.8 × $10^{-2}$ m

total charge (q) =6.1× $10^{-7}$ C

To solve:

volume charge density (ρ)

We know;

ρ =q ÷ v

volume of cylinder = π ×r × r × h

volume of cylinder =3.14 × 2.1 × 2.1 × $10^{-4}$ × 8.8 × $10^{-2}$

volume of cylinder (v) = 122.23 × $10^{-6}$

ρ =q ÷ v

ρ = 6.1× $10^{-7}$ ÷ 122.23 × $10^{-6}$

ρ = 0.04 × $10^{-1}$ C

Therefore the volume charge density of a substance (ρ) is 0.04 × $10^{-1}$ C.

3 0

3 years ago

What is the primary type of battery we use today to store energy?

Ahat [919]

Lithium-Ion batteries are commonly used in portable electronics and electric vehicles. These rechargeable batteries have two electrodes: one that's positively charged and contains lithium and another negative one that's typically made of graphite.

4 0

3 years ago

Read 2 more answers

What instrument measures air temperature?

zavuch27 [327]

Its a thermometer . i hope this helps you

5 0

3 years ago

A 10-kg package drops from chute into a 25-kg cart with a velocity of 3 m/s. The cart is initially at rest and can roll freely w

amid [387]

Answer:

(a) the final velocity of the cart is 0.857 m/s

(b) the impulse experienced by the package is 21.43 kg.m/s

Explanation:

Given;

mass of the package, m₁ = 10 kg

mass of the cart, m₂ = 25 kg

initial velocity of the package, u₁ = 3 m/s

initial velocity of the cart, u₂ = 0

let the final velocity of the cart = v

(a) Apply the principle of conservation of linear momentum to determine common final velocity for ineleastic collision;

m₁u₁ + m₂u₂ = v(m₁ + m₂)

10 x 3 + 25 x 0 = v(10 + 25)

30 = 35v

v = 30 / 35

v = 0.857 m/s

(b) the impulse experienced by the package;

The impulse = change in momentum of the package

J = ΔP = m₁v - m₁u₁

J = m₁(v - u₁)

J = 10(0.857 - 3)

J = -21.43 kg.m/s

the magnitude of the impulse experienced by the package = 21.43 kg.m/s

(c)

the initial kinetic energy of the package is calculated as;

$K.E_i = \frac{1}{2} mu_1^2\\\\K.E_i = \frac{1}{2} \times 10 \times (3)^2\\\\K.E_i = 45 \ J\\\\$

the final kinetic energy of the package;

$K.E_f = \frac{1}{2} (m_1 + m_2)v^2\\\\K.E_f = \frac{1}{2} \times (10 + 25) \times 0.857^2\\\\K.E_f = 12.85 \ J$

the fraction of the initial energy lost;

$= \frac{\Delta K.E}{K.E_i} = \frac{45 -12.85}{45} = 0.71$

7 0

3 years ago