1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
masya89 [10]
3 years ago
13

A roller coaster has a mass of 650 kg. It sits at the top of a hill with height 78 m. If it drops from this hill, how fast is it

going when it reaches the bottom? (Assume there is no air resistance or friction.)
Physics
1 answer:
Leto [7]3 years ago
5 0

Answer:

The roller coaster is going at 39.1 m/s when it reaches the bottom

Explanation:

We use conservation of mechanical energy to solve this problem. So, we need to estimate the potential energy of the cart at the top of the hill while it is sitting steady there. Such will give us the cart initial Total Energy (TE) since its kinetic energy at that moment is zero (the cart is not moving, just sitting at the top of the hill).

Its initial potential energy (Ui) is therefore: Ui=m*g*h=650 * 9.8 * 78=496860 J

Notice also that all units given are in the SI system, (including the acceleration of gravity g) and therefore the answer is in Joules.

As we said, this initial potential energy equals the Total Energy  (TE) of the roller coaster because its initial Kinetic Energy (Ki) is zero.

When we look at what happens the instant the cart reaches the bottom, at that point it has all kinetic energy and zero potential energy (h is zero at the bottom of the hill). Final Kinetic Energy is by definition: Kf =\frac{1}{2} m*v^2=\frac{1}{2}650*v^2=325 v^2

Therefore, the conservation of mechanical energy tells us that:

ET_i=ET_F\\U_i+K_i=U_F+K_F\\496860 J +0J=0J+325v^2

We can solve for the final velocity of the roller coaster in this equation by solving for it in the equation:

496860 J +0J=0J+325v^2\\\\496860J=325v^2\\v^2=\frac{496860}{325} =1528.8\\v=\sqrt{1528.8} = 39.1 \frac{m}{s}

The velocity should result with units of meters/second since all quantities were given in SI units.

You might be interested in
Does the eruption from a volcano represent force
kkurt [141]

Answer:

Yes, because of the force of gas exploding the volcano from pressure is a force.

6 0
3 years ago
A soccer player carries the ball for a distance of 40.0 m in the direction 42.0° west of south. find the westward component of t
Maksim231197 [3]

Actually what the problem meant about the westward component of the ball’s displacement is the horizontal component of the displacement. To help us better understand the problem, I attached a figure of the situation.

We can see from the figure that to solve for the value of the horizontal component, we have to make use of the sin function. That is:

sin θ = side opposite to the angle / hypotenuse of the triangle

sin 42 = x / 40 m

x = (40 m) sin 42

x = 26.77 m

 

Therefore the ball has a westward displacement of about 26.77 m

3 0
3 years ago
The mass of an object changes as the distance from the center of gravity changes.
Alchen [17]

Answer:

true

Explanation:

this is the answer to this question

8 0
3 years ago
Describe the difference between contact forces and field forces.
Salsk061 [2.6K]
Contact forces has to be touching for it to be an actual force. A field force does not have to be touching but it does have to be acting on particles at different positions in a space.
8 0
3 years ago
The magnitude J(r) of the current density in a certain cylindrical wire is given as a function of radial distance from the cente
Gennadij [26K]

Answer:

18.1 × 10⁻⁶ A = 18.1 μA

Explanation:

The current I in the wire is I = ∫∫J(r)rdrdθ

Since J(r) = Br, in the cylindrical wire. With width of 10.0 μm, dr = 10.0 μm. r = 1.20 mm. We have a differential current dI. We integrate first by integrating dθ from θ = 0 to θ = 2π.

So, dI = J(r)rdrdθ

dI/dr = ∫J(r)rdθ = ∫Br²dθ = Br²∫dθ = 2πBr²

Now I = (dI/dr)dr at r = 1.20 mm = 1.20 × 10⁻³ m and dr = 10.0 μm = 0.010 mm = 0.010 × 10⁻³ m

I = (2πBr²)dr = 2π × 2.00 × 10⁵ A/m³ × (1.20 × 10⁻³ m)² × 0.010 × 10⁻³ m  =  0.181 × 10⁻⁴ A = 18.1 × 10⁻⁶ A = 18.1 μA

3 0
3 years ago
Other questions:
  • Is the color spectrum simply a small segment of the electromagnetic spectrum?
    9·1 answer
  • What would the answer be ?
    11·1 answer
  • The difference in electronegativity values between H and O is 1.4. What type of bond will these elements form?
    10·1 answer
  • The chandra x-ray observatory is used to study _____.
    6·2 answers
  • What color will a star be with a surface temperature of 5000–6000 K?
    15·2 answers
  • Which method is used to deliver heat in most central heating systems?
    15·2 answers
  • Which electromagnetic wave enables us to see objects?
    9·2 answers
  • The Sun produces energy when_
    5·1 answer
  • An object has a. Kinetic energy of 17j and a mass of 27 kg, how fast is the object moving?
    14·1 answer
  • A 1200 kg car traveling east at 4.5 m/s crashes into the side of a 2100 kg truck that is not moving. During the collision, the v
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!