Projectile Motion: How High is the Cliff?

What is the height of the cliff that a kangaroo jumped off of with a speed of 6.0 m/s at an angle of 28.0° above the horizontal, landing 8.00 meters horizontally from the starting point? The height of the cliff can be determined using the equations of projectile motion. By breaking down the initial velocity of the kangaroo into horizontal and vertical components, and then utilizing the horizontal displacement and time of flight, we can calculate the height of the cliff.

When a kangaroo jumps off a cliff, its motion can be analyzed using the principles of projectile motion. In this scenario, the kangaroo has an initial speed of 6.0 m/s at an angle of 28.0° above the horizontal. To find the height of the cliff from which the kangaroo jumped, we need to consider both the horizontal and vertical components of its motion.

Horizontal Motion:

The kangaroo lands 8.00 meters horizontally from the starting point. This horizontal displacement, combined with the initial velocity and launch angle, allows us to calculate the time of flight for the kangaroo. Using the equation:

Horizontal displacement = horizontal velocity * time

We can determine the time it took for the kangaroo to land horizontally. This time will be used in the vertical motion calculations.

Vertical Motion:

The vertical component of the kangaroo's initial velocity can be calculated using the sine of the launch angle:

Vertical velocity = initial velocity * sin(angle)

Once we have the vertical velocity, we can use it to find the time it takes for the kangaroo to reach the maximum height. From there, we can calculate the height of the cliff using the equation of motion:

y = y_0 + v_y(t) + (1/2)gt^2

Where:

  • y = final height (height of the cliff)
  • y_0 = initial height (0 in this case, as we are measuring the height from the starting point)
  • v_y = vertical component of velocity
  • t = time of flight
  • g = acceleration due to gravity (approximately 9.81 m/s^2)

By substituting the known values into the equation and solving for y, we can determine the height of the cliff from which the kangaroo jumped. This method allows us to utilize the principles of projectile motion to analyze and solve for the vertical displacement in this scenario.

Understanding projectile motion and its applications can provide valuable insights into various real-world situations involving the motion of objects in two dimensions. The ability to break down motion into horizontal and vertical components allows for precise calculations and predictions, making it a fundamental concept in physics.

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