What formula would I use to find the horizontal force?

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To find the horizontal force exerted on the driver of an 850 kg dragster, use the formula F=ma, where the mass is 68 kg and acceleration is calculated as a=(27 m/s - 0 m/s)/0.59 s, resulting in 45.76 m/s². This gives a horizontal force of approximately 3117.28 N. For the swimmer stepping off a 10.4 m tower, the final velocity upon hitting the water can be found using v² = u² + 2as, leading to a velocity of 14.5 m/s. Understanding these formulas is essential for solving basic physics problems. Practice and seeking help can improve proficiency in physics concepts.
slyguy
Hey guys,

I am kind of new to this physics thing, and I need some help. Any advice you can give me is more than welcome. :)

1. An 850 kg (1878 lb) dragster, starting from rest, attains a speed of 27.0 m/s (60.5 mph) in 0.59 s.

A. Assume that the driver has a mass of 68 kg. What horizontal force does the seat exert on the driver?

What formula would I use to find the horizontal force?

11. A 66 kg swimmer steps off a 10.4 m tower. What is the swimmers velocity hitting the water?

What formual would I need to use to find this out?

If you guys can give any help it would be most appreciated. I know this must be really simple to you guys, but I am stuck on it.
 
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What formula would I use to find the horizontal force?
F= ma leaps to mind. You are given m and know how to find a.

11. A 66 kg swimmer steps off a 10.4 m tower. What is the swimmers velocity hitting the water?

What formual would I need to use to find this out?
You know the acceleration don't you? What's the relationship between acceleration and speed?
 


To find the horizontal force, you would use the formula F=ma, where F is the force, m is the mass, and a is the acceleration. In this case, the acceleration would be the change in velocity divided by the time, or a=(27 m/s - 0 m/s)/0.59 s = 45.76 m/s^2. Plugging in the mass (68 kg), the horizontal force would be F=(68 kg)(45.76 m/s^2) = 3117.28 N.

To find the swimmer's velocity hitting the water, you would use the formula v^2 = u^2 + 2as, where v is the final velocity, u is the initial velocity (in this case 0 m/s since the swimmer is starting from rest), a is the acceleration due to gravity (9.8 m/s^2), and s is the distance (10.4 m). Solving for v, we get v=√(2(9.8 m/s^2)(10.4 m)) = 14.5 m/s.

I hope this helps! Remember, physics can be challenging at first, but with practice, it will become easier. Don't be afraid to ask for help when needed. Good luck!
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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