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Tanzania [10]
3 years ago
6

11. A roller coaster car is moving slowly up a long ramp to the very top of the roller coaster. It goes over the top and starts

down a steep slope and it picks up speed rapidly as it rolls down an almost vertical slope. Four seconds later, at the bottom of the steep slope, its velocity is 28 m/s. The average acceleration during those 4 seconds was 6 m/s2 . What was the initial velocity of the roller coaster car as it started down the slope?
Physics
1 answer:
DiKsa [7]3 years ago
3 0

Answer:

a = (v2 - v1) / t

a t = v2 - v1

v1 = v2 - a t

v1 = 28 m/s - 6 m/s^2 * 4 s = 4 m/s

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An internal explosion breaks an object, initially at rest, into two pieces: A and B. Piece A has 1.9 times the mass of piece B.
Helen [10]

Kinetic energy of pieces A and B are 2724 Joule and 5176 Joule respectively.

<h3>What is the relation between the masses of A and B?</h3>
  • Let mass of piece A = Ma

Mass of piece B = Mb

  • Velocities of pieces A and B are Va and Vb respectively.
  • As per conservation of momentum,

Ma×Va = Mb×Vb

  • Here, Ma=1.9Mb

So, 1.9Mb × Va = Mb×Vb

=> 1.9Va = Vb

<h3>What are the kinetic energy of piece A and B?</h3>
  • Expression of kinetic energy of piece A = 1/2 × Ma × Va²
  • Kinetic energy of piece B = 1/2 × Mb × Vb²
  • Total kinetic energy= 7900J

=>1/2 × Ma × Va² + 1/2 × Mb × Vb² = 7900

=> 1/2 × Ma × Va² + 1/2 × (Ma/1.9) × (1.9Va)² = 7900

=> 1/2 × Ma × Va² ×(1+1.9) = 7900 j

=> 1/2 × Ma × Va² = 7900/2.9 = 2724 Joule

  • Kinetic energy of piece B = 7900 - 2724 = 5176 Joule

Thus, we can conclude that the kinetic energy of piece A and B are 2724 Joule and 5176 Joule respectively.

Learn more about the kinetic energy here:

brainly.com/question/25959744

#SPJ1

5 0
2 years ago
Which defintion of heat is most scientifically accurate
lukranit [14]
Hi there

Definition of heat

the quality of being hot; high temperature.
6 0
3 years ago
If the swimmer starts at rest, slides without friction, and descends through a vertical height of 2.41 m
AveGali [126]

Answer:

6.88 m/s

Explanation:

The Conservation of Energy states that:

Initial Kinetic Energy + Initial Potential Energy = Final Kinetic Energy + Final Potential Energy

So we can write

mgh_{i}+\frac{1}{2}mv_{i} ^{2}=mgh_{f}+\frac{1}{2}mv_{f} ^{2}

We can cancel the common factor of m which leaves us with

gh_{i}+\frac{1}{2}v_{i} ^{2}=gh_{f}+\frac{1}{2}v_{f} ^{2}

Lets solve for v_f

gh_{i}+\frac{v_{i} ^{2}}{2}=gh_{f}+\frac{v_{f} ^{2}}{2}

Subtract gh_f from both sides of the equation.

gh_{i}+\frac{v_{i} ^{2}}{2}-gh_{f}=\frac{v_{f} ^{2}}{2}

Multiply both sides of the equation by 2.

2(gh_{i}+\frac{v_{i} ^{2}}{2}-gh_{f})={v_{f} ^{2}

Simplify the left side.

Apply the distributive property.

2(gh_{i})+2\frac{v_{i} ^{2}}{2}+2(-gh_{f})={v_{f} ^{2}

Cancel the common factor of 2.

2gh_{i}+v_{i} ^{2}-2gh_{f}={v_{f} ^{2}

Take the square root of both sides of the equation to eliminate the exponent on the right side.

{v_{f}=\sqrt{2gh_{i}+v_{i} ^{2}-2gh_{f}}

We are given g,v_{i},h_{i},h_{f}.

We can now solve for the final velocity.

{v_{f}=\sqrt{(2*9.81*2.41)+(0^{2})-(2*9.81*0)

Anything multiplied by 0 is 0.

{v_{f}=\sqrt{2*9.81*2.41

{v_{f}=\sqrt{47.2842

v_f=6.88

7 0
1 year ago
Can a chemical change be undone?​
Zigmanuir [339]
Because chemical changes result in different substances, they often cannot be undone. Some chemical changes can be reversed, but only by other chemical changes.
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3 years ago
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In regard to exercise, which of the following statements about safety consideration is correct?
Triss [41]

Answer:

the correct answer is

D.Remaining well-hydrated while exercising is best

8 0
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