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GenaCL600 [577]

4 years ago

7

An object is initially moving at an unknown velocity. It accelerates at a rate of 2.0 m/s2 to a new velocity of 45 m/s in 10s. W

hat was the initial velocity?

1 answer:

katrin2010 [14]4 years ago

6 0

Answer:

Initial velocity=25m/s

Explanation:

acceleration(a)=2m/s^2

Final velocity(v)=45m/s

Time(t)=10seconds

Initial velocity(u)=?

V=u+axt

45=u+2x10

45=u+20

u=45-20

u=25m/s

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A sandbag motionless in outer space is hit by a three-times-as massive sandbag moving at 12 m/s. They stick together. This is an

vekshin1

Answer:

This is an example of inelastic collision and it loses zero(0) % of initial kinetic energy

Explanation:

Let the mass of the motionless sandbag = m₁

Let the mass of the moving sandbag = m₂ = 3m₁

initial velocity of the motionless sandbag, u₁ = 0

initial velocity of the moving sandbag, u₂ = 12 m/s

Let their final velocity, = v

Collision between two particles can either be elastic or inelastic.

Since they stick together after the impact, then the collision is inelastic

Apply the principle of conservation of linear momentum;

Initial kinetic energy = final kinetic energy

¹/₂m₁u₁² + ¹/₂m₂u₂² = ¹/₂v²(m₁ + m₂)

¹/₂m₁(0)² + ¹/₂(3m₁)(12)² = ¹/₂v²(m₁+3m₁)

216m₁ = 2m₁ v²

v² = 108

v = √108

v = 10.392 m/s

Change in kinetic energy = Final kinetic energy - initial kinetic energy

Initial Kinetic energy, KE₁ = ¹/₂m₁u₁² + ¹/₂m₂u₂²

KE₁ = ¹/₂m₁(0)² + ¹/₂(3m₁)(12)²

KE₁ = 216m₁ J

Final kinetic energy, KE₂ = ¹/₂v²(m₁ + m₂)

KE₂ = ¹/₂(108)(m₁ + 3m₁)

KE₂ = 216m₁ J

ΔKE = KE₂ - KE₁ = 216m₁ J - 216m₁ J = 0%

Therefore, this is an example of inelastic collision and it loses zero(0) % of initial kinetic energy

4 0

3 years ago

An object is moving with a constant velocity of 278 m/s. How long will it take it to travel 7500 m, using the formula Delta X=Vt

rusak2 [61]

If the velocity is constant then the acceleration of the object is zero.
$a=0 (m/s^2)$
Thus when we apply the equation
$\Delta X=vt+(at^2/2)$
It remains
$\Delta X =vt$
or equivalent
$t=(\Delta X/v) =7500/278 =26.98 (seconds)$

7 0

4 years ago

State the law of conversation of momentum

Sliva [168]

The total momentum before a collision is equal to the total momentum after the collision if no external forces act on the system.
Hope this helps

6 0

3 years ago

Two Objects of the same size will always have the same mass” Is this statement correct?

attashe74 [19]

No, they won't, mass coincides with density and objects have different densities a one pound lead ball would be smaller than a one pound copper one.

6 0

3 years ago

Suppose you want to test the hypothesis that plants grow taller when they receive more sunlight. Identify and independent variab

ollegr [7]

The result that should be established is in the form
y = f(x)
where x, the amount of sunlight is the controlled (independent) variable,
y = height (growth) that corresponds to the amount of sunlight. Therefore y depends on x.

Clearly,
x, the amount of sunlight is the independent variable. It can be controlled.
y, the measured amount of growth is the dependent variable.

Answer:
The independent variable is the amount of sunlight.
The dependent variable is the growth.

5 0

4 years ago