# How Fast is a Balloon Rising if a Dropped Coin Hits the Ground in 4 Seconds?

• fraserperry
In summary, the conversation discusses a motion question involving a balloon and a coin being dropped from it. The goal is to find the speed of the balloon using the motion equation and the time it takes for the coin to reach the ground. The conversation also clarifies that the initial velocity of the coin is equal to the constant velocity of the balloon, and they both experience a change in acceleration due to gravity. The final answer for the balloon's velocity is 12.1 m/s.
fraserperry
Hard Motion Question- Help?

I am really stuck on this motion question, can anyone help please?

"A balloon is 30.00m above the ground and is rising vertically with a uniform speed when a coin is dropped from it. If the coin reaches the ground in 4.00 seconds, what is the speed of the balloon?

So, the coin has an initial height of 30 m, and an initial velocity of v. It has a constant acceleration of -9.8 m/s^2. Find the time it takes to fall to a height of 0 m, in terms of your variables v and t. Then plug in 4.00 s for t, and solve for v.

which motion equation do i use?

solve for the initial velocity of the coin,,since it is equal to the constant velocity of the balloon, try

0 = 30 + Vi * 4 - .5g(4^2)

thing to know is that if the balloon is traveling , say 500 m/s when the coin is dropped...the coin is actually dropped AT 500m's...so its initial velocity when you insert it into an equation is 500m/s,, NOT 0 as you might assume.
though that's irrelevant here, thought i might say. so that you understand the purpose of the question really

are you saying the coin when dropped is would be traveling the same speed of the balloon in an upwards direction?

yes, you and its acceleration is changed from 0 to -9.8 when you put it in the equation because of gravity...because of course it will be hitting the ground soon

I got 12.1 from that equation, but what is that number?

the coins initial velocity once it is released from the balloon. = 12.1

which just so happens to be the balloons constant velocity, since when you initially dropped the coin from the balloon its initial velocity is = to the balloon velocity.
so, Balloon-velocity = 12.1

ithink

## 1. What is hard motion?

Hard motion is a term used to describe the movement of an object that requires a significant amount of force or energy to change its position or direction. It can be caused by factors such as friction, gravity, or inertia.

## 2. What are some examples of hard motion?

Some examples of hard motion include pushing a heavy object, climbing a steep hill, or throwing a ball with a lot of force. Essentially, any movement that requires a considerable amount of effort can be considered hard motion.

## 3. How is hard motion different from regular motion?

Hard motion is different from regular motion because it requires more energy or force to achieve the same amount of movement. In regular motion, the object may move more easily and with less effort.

## 4. What factors affect hard motion?

Several factors can affect hard motion, including the mass of the object, the surface it is moving on, and the amount of force applied. Additionally, factors such as air resistance and friction can also impact hard motion.

## 5. How can I calculate hard motion?

To calculate hard motion, you need to know the mass of the object, the force applied, and the friction or resistance on the object. You can use formulas such as Newton's Second Law of Motion or the Work-Energy Theorem to determine the amount of force needed to move the object a certain distance.

• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
12
Views
3K
• Introductory Physics Homework Help
Replies
2
Views
2K
• Introductory Physics Homework Help
Replies
10
Views
1K
• Introductory Physics Homework Help
Replies
10
Views
2K
• Introductory Physics Homework Help
Replies
2
Views
4K
• Introductory Physics Homework Help
Replies
2
Views
3K
• Introductory Physics Homework Help
Replies
12
Views
3K
• Introductory Physics Homework Help
Replies
4
Views
3K
• Introductory Physics Homework Help
Replies
3
Views
2K