# How Fast is a Golf Ball Traveling 10m After Being Dropped from a Cliff?

• Michael17
In summary, a golf ball is dropped from a 78m high cliff without air resistance and gravity of 9.8ms^-2. We want to know its speed at 10m from the initial position. Using the formula v²=u²+2as, we can calculate that the ball is traveling at a speed of 14 m/s. However, it is more beneficial to understand the problem step by step instead of just using the formula. By introducing time, we can express v in terms of a and t, and then use the formula s=average speed × time to solve for t. This method may be longer, but it helps with better understanding and deriving the kinematics formulas listed in the conversation.
Michael17
Golf balls and cliffs!

Hi I'm new to this forum and a novice in physics could anyone please help me with this question?

A golf ball is droped from the top of a sheer cliff 78m high. If gravity is 9.8ms^-2 and there is no air resistance, what speed is it traveling at 10m from its initial position?

Please try using the following formulae:

https://www.physicsforums.com/showpost.php?p=905663&postcount=2

You have the initial speed as it's dropped from rest; you have a value for the acceleration due to gravity; you have the displacement that it travels. One of the 1D kinematics equations will be able to help you.

What you should do is write all the information that you have, or you want, in a list.

u = 0 (initial velocity)
v = v (final velocity, we don't know this)
a = 9.8 (acceleration)
s = 10 (distance traveled)
t = ? (time taken, we don't need to know this)

then use the formula:

v²=u²+2as (then put in that values you know)
v²=0+2*9.8*10
v²=196
v= 14 m/s

The other formulas that you might need are:

v = u + at
s = 0.5t(u+v)
s = ut +0.5at²
v² = u² + 2as

Hi, welcome to PF. Just to let you know, there is a homework help section for these kinds of questions. If you have more homework questions in future, you'll get the most helpful support if you ask them there.

Ok, so for this question you could just insert your values of $a$ and $s$ into whichever formula seems to fit, as is too often taught in schools, and in doing so stumble across the correct answer. But you learn much more if you ignore the formulas and work out the answer step by step.

Here, $u$ = 0 m/s, $a$ = 9.8 m/s$^2$, $s$ = 10 m and $v$ is the unknown. (At this point you could simply use $v^2=u^2+2as$, but please abstain from doing that until you're satisfied you understand where that formula from.)

The most intuitive way to visualise these types of question (in my opinion) is to introduce time. It's just easier to visualise what will happen to the ball/projectile over time, rather than over distance.

I'd start by expressing $v$ in terms of $a$ and $t$ ($u$ is zero so you can ignore it. Zero plus anything is zero.) Next: given that your formula contains the initial and final velocities, express the average velocity of the ball over time period $t$. Next: Distance = average speed × time. You'll end up with a formula that starts with "$s=...$". Finally, let $s$=10 and solve for $t$.

This is really an unnecessarily long method, but by thinking several similar problems through in the same way you'll understand how to solve them. Next, derive for yourself the kinematics formulae listed in Georgepowell's post. Then you will have "earned the right" to cheat by using the formulas straight off the bat!

- m.e.t.a.

## 1. What happens when a golf ball is hit off a cliff?

When a golf ball is hit off a cliff, it will follow the laws of physics and fall towards the ground due to the force of gravity. The speed and trajectory of the ball will depend on the angle and force of the initial hit, as well as any wind or other external factors.

## 2. Can a golf ball bounce off a cliff?

Yes, a golf ball can bounce off a cliff if it lands on a surface that is angled in a way that allows it to rebound. However, the height and angle of the cliff, as well as the materials it is made of, can affect the likelihood of a bounce occurring.

## 3. Will a golf ball break if it falls off a cliff?

It is possible for a golf ball to break if it falls off a cliff, depending on the height of the cliff and the type of surface it lands on. A harder surface, such as rocks or concrete, may cause the ball to shatter upon impact, while a softer surface like grass or sand may cushion the fall and prevent it from breaking.

## 4. How far can a golf ball travel when hit off a cliff?

The distance a golf ball can travel when hit off a cliff will depend on several factors, including the height and angle of the cliff, the force and angle of the initial hit, and any external factors such as wind. In some cases, a golf ball hit off a cliff can travel hundreds of yards before coming to a stop.

## 5. Is it safe to hit a golf ball off a cliff?

Hitting a golf ball off a cliff can be dangerous, as there is a risk of the ball hitting someone or causing property damage if it lands in populated or built-up areas. It is important to always take precautions and assess the potential risks before hitting a golf ball off a cliff.

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