EjerciciosFyQ

Acceleration and time taken by a car to increase speed (8329)

F_y_Q — 2024-10-10T03:34:15Z

A car, which has uniformly accelerated motion, increases its speed from 18 km/h to 72 km/h over a straight distance of 37.5 meters. Calculate the time taken for this journey and its acceleration.

To make the problem homogeneous, the first step is to express the speeds in SI units:

You can relate the change in speed and the distance covered with the car's acceleration:

Substitute the values and calculate:

The time needed to make this speed change is:

Substitute and calculate:

Calculation of braking acceleration (8312)

F_y_Q — 2024-09-16T03:46:33Z

Determine the acceleration of a car, initially moving at a speed of 120 km/h, knowing that it takes 20 seconds to come to a complete stop.

The car will have changed its speed by 120 km/h in those 20 seconds. First, convert the speed to International System units:

The acceleration will be:

Vertical upward lunch (8289)

F_y_Q — 2024-08-15T05:47:50Z

A body is launched vertically upwards with an initial velocity of . How long will it take to reach its maximum height?

Since it is a vertical upward launch, if you take the initial velocity as positive, the gravitational acceleration must be negative. The velocity of the object at any instant can be obtained from the expression:

The condition for the body to stop ascending is that the velocity is zero; at that moment, it will have reached its maximum height. By imposing this condition on the previous equation, you can solve for the time and calculate it:

Angular position and velocity of a wheel (7424)

F_y_Q — 2021-12-10T05:42:50Z

The angular velocity of a bicycle wheel is , and its angular acceleration is .

a) What are the angular position and angular velocity at t = 5 s?

b) What are the angular position and angular velocity at t = 5 s, expressed in revolutions?

c) What are the final velocity and displacement of the bicycle at t = 5 s if the tire has a diamater of 1 meter?

a) The equation for angular velocity is:

Using the given values:

The equation for angular position is:

Using the given values:

b) To convert angular velocity and position to revolutions:

For angular position:

c) To convert angular quantities into linear quantities, use the wheel radius:

Download the statement and the solution of the problem in EDICO format if you need it.

Acceleration of a car (3583)

F_y_Q — 2016-05-22T06:35:14Z

A car is increasing its speed from 40 m/s to 70 m/s. What is its acceleration if the time needed was 3 seconds?

Acceleration is defined by:

Replace the problem data:

Descarga el enunciado y la resolución del problema en formato EDICO si lo necesitas.

Time taken to cover a distance by car (3567)

F_y_Q — 2016-05-06T04:55:51Z

If the speed of a car is 75 km/h. How long does it take the car to cover a distance of 75 km?

Using the definition of speed:

Rearranging the formula to solve for time:

Substituting the given values:

Descarga el enunciado y la resolución del problema en formato EDICO si lo necesitas.