Recent content by Smartgurl

So I went back and read everything. Then I found the energy by using q=mcΔt and got 8.85 x 10^4 J. Now I think I use the equation E=mc^2 and solve for m.

The chapter is about special relativity. However I believed it had nothing to do with the unit because I don't see how it has anything to do with the topic. I don't remember reading anything about temperature in this topic and I don't think I have any equations that can work for this.

Thats the whole question and all the info I know. It's part of an independent study so I have no examples or notes or anything to look off of. That's why I have no idea how to start it.

Homework Statement Using coffee (specific heat capacity of 3.98 x 10^3 J/kg °C) calculate the increase in mass if you raised the temperature of a 353 g cup of coffee from 34° C to 97°C. Homework Equations Q=mcΔt The Attempt at a Solution I believe I just need to solve for m. However I have...

Homework Statement A 250 g object is dropped from a height of 150 m. What is the kinetic energy after falling to 100m Homework Equations V2^2 = V1^2 +2ad Ek = 1/2 mv^2 The Attempt at a Solution I used the kinematics equation to find my v2 then I used this to find Ek. I got the answer 120J but...

Yes it does! I guess it's one of those rare occasions when the textbook is wrong! Thanks! I'll definitely make sure the answer is reasonable next time

No now that I think about it that's not reasonable. Does that mean I'm actually doing it right?

Homework Statement A small truck is equipped with a rear bumper that has a spring constant of 8 x 10^5 N/m. The bumper can be compressed 15 cm without causing damage to the truck. What is the maximum velocity with which a solid 1000kg car can collide with the bumper without causing damage to...

Thank you so much! Now it seems simple since I understand it

I drew a diagram and I think that when the mass is at the top it will need the minimum Fc as gravity will help bring it down. Where at the bottom the Fc will have to overcome gravity to bring the mass back up. So gravity will be the only force acting on the mass and bringing it down when it is...

Would Fg = Fc? So I could get mg = m4(pi)^2rf^2. Then solve for f?

Is the equation Fc = m4(pi)^2rf^2

Homework Statement A mass of 2.0 x 10^2 g is tied to a 1.6 m long string and spun in a vertical circle. What is the minimum frequency to keep the mass moving? Homework Equations Fc=m4(pie)rf^2 The Attempt at a Solution I know I have to use this equation and make it equal to another to find Fc...

Yes it says south.

Homework Statement A ships captain wishes to sail his ship north -east. A current is moving his ship with a velocity of 5.0km/h . If the ship has a maximum speed of 30 km/h what is the ships required heading? Homework Equations Cos angle=A/H The Attempt at a Solution Heading=cosine (5/30)...