Question

Round answer to the nearest tenth. A hang glider dropped his cell phone from a height of 350 feet. How many seconds did it take for the cell phone to reach the ground?

Answer 1

Answer:

The cell phone took 4.7 seconds to reach the ground.

Step-by-step explanation:

A hang glider dropped his cell phone from a height of 350 feet:

Initial velocity: Vo = 0 ft/s

Height: h = 350 feet = 350 ft

Time to reach the ground: t=?

Gravity's acceleration: g = 32 ft/s^2

h = Vo t + g t^2 / 2

Replacing the known values in the equation above:

350 ft = (0 ft/s) t + (32 ft/s^2) t^2 /2

350 ft = 0 + (16 ft/s^2) t^2

350 ft = (16 ft/s^2) t^2

Solving for t^2: Dividing both sides of the equation by 16 ft/s^2:

(350 ft) / (16 ft/s^2) = (16 ft/s^2) t^2 / (16 ft/s^2)

21.875 s^2 = t^2

Solving for t: Square root both sides of the equation:

sqrt(21.875 s^2) = sqrt(t^2)

4.677071733 s = t

t = 4.677071733 s

Rounding to the nearest tenth:

t = 4.7 s

Answer 2

The cell phone takes about 4.7 seconds to reach the ground

Further explanation

Acceleration is rate of change of velocity.

$\large {\boxed {a = \frac{v - u}{t} } }$

$\large {\boxed {d = \frac{v + u}{2}~t } }$

a = acceleration ( m/s² )

v = final velocity ( m/s )

u = initial velocity ( m/s )

t = time taken ( s )

d = distance ( m )

Let us now tackle the problem!

Given:

Height = h = 350 feet

Gravitational Acceleration = g = 32.2 feet/s²

Initial Velocity = u = 0 m/s

Unknown:

time taken to reach the ground = t = ?

Solution:

This problem is about Free Fall.

When an object experiences free fall, the acceleration experienced by the object is the same as the acceleration due to gravity which is equal to 9.8 m/s² or 32.2 feet/s²

$h = ut + \frac{1}{2}gt^2$

$350 = 0t + \frac{1}{2}(32.2)t^2$

$350 = 0 + 16.1t^2$

$t^2 = 350 \div 16.1$

$t \approx 4.7 ~ \text{seconds}$

Learn more

• Velocity of Runner : brainly.com/question/3813437
• Kinetic Energy : brainly.com/question/692781
• Acceleration : brainly.com/question/2283922
• The Speed of Car : brainly.com/question/568302

Answer details

Grade: High School

Subject: Physics

Chapter: Kinematics

Keywords: Velocity , Driver , Car , Deceleration , Acceleration , Obstacle