Homework Help: Physics

Posted by Priscilla on Tuesday, February 2, 2010 at 9:23pm.

I really need help with only this two problems.

1. A 6.0 kh block, sliding to the east across a horizontal, frictionless surface with a momentum of 30 kg*m/s^, strikes an obstacle. The obstacle exerts an impluse of 10 N*s to the west on the book. The speed of the block after the collision is...

2. While riding a chairlift, a 55 kg skier is raised a vertical distance of 370 m. what is the total change in the skier's gravitional potential energy? given: m = 55 kg d = 370 m When i used PE = mgh, the answer was 199,430, i know its wrong since the answer is something else. But what equation can i use?

Physics - drwls, Tuesday, February 2, 2010 at 9:35pm
1. Is kh supposed to be kg? Are the block and the book the same object?

Whatever. The applied impulse equals the reduction in momentum of the block/book.

2. Your answer is correct and you used the right equation. Perhaps they want you to use only two significant figures (200,000 J) which is the same number of significant figures as the 9.8 m/s^2 and the 55 kg). You also must include the units (J) in your answer.
Physics - Priscilla, Tuesday, February 2, 2010 at 9:40pm
Ok, i understand question 2, i realize what i did wrong. But i dont understand question 1.
Physics - Priscilla, Tuesday, February 2, 2010 at 9:43pm
Ok thanks. Yes, for question 1, its 6 kg, sorry.
Physics - Priscilla, Tuesday, February 2, 2010 at 9:44pm
yes, is it j = m(change)v that i have to use for question 1
Physics - Priscilla, Tuesday, February 2, 2010 at 9:50pm
No, theres no book in this question only block.
Physics - drwls, Tuesday, February 2, 2010 at 11:24pm
<<The obstacle exerts an impulse of 10 N*s to the west on the book.>>

Looks like "book" to me

The impulse equals the momentum change, which is M times the velocity change

Answer this Question

Related Questions

Physics - A 6.0 kh block, sliding to the east across a horizontal, frictionless ...
physics - really confused, A 2kg box is sliding east at 50m/s on a frictionless ...
Physics 12 - Ohmygoodness, I am not having a good time tonight. "A 5.2kg ...
physics - A 4.0-kg block is stacked on top of a 12.0-kg block, which is ...
Physics - A 15-kilogram block is sliding on a dry, level surface with a ...
Physics - A 4.0 kg block is stacked on top of a 12.0 kg block, whcih is ...
Physics - You push a 2.5 kg block against a horizontal spring, compressing the ...
physics - You push a 1.9 kg block against a horizontal spring, compressing the ...
physics - You push a 2.0 kg block against a horizontal spring, compressing the ...
physics - You push a 4.6 kg block against a horizontal spring, compressing the ...

For Further Reading

First Name:
School Subject:
Answer: