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?

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.

Ok, i understand question 2, i realize what i did wrong. But i don't understand question 1.

Ok thanks. Yes, for question 1, its 6 kg, sorry.

yes, is it j = m(change)v that i have to use for question 1

No, theres no book in this question only block.

<<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

Sure, I can help you with both of these problems!

1. To find the speed of the block after the collision, you can use the principle of conservation of momentum. The equation for conservation of momentum is:

Initial momentum = Final momentum

The given information tells us that the initial momentum of the block is 30 kg*m/s^ (east direction) and the impulse exerted by the obstacle is 10 N*s (west direction). The impulse is given by the equation:

Impulse = Change in momentum

So, we can rewrite the equation as:

30 kg*m/s^ - 10 N*s = Final momentum

To find the final momentum, we need to convert the impulse from N*s to kg*m/s^ by dividing it by the time taken. Since the time is not provided, we can assume that it is an instantaneous collision, which means the final momentum is simply the impulse.

Final momentum = 10 kg*m/s^ (west direction)

To find the speed, we can use the equation for momentum:

Momentum = mass * velocity

Rearranging the equation, we get:

Velocity = Momentum / mass

Substituting the values, we get:

Velocity = 10 kg*m/s^ / 6.0 kg = 1.67 m/s (west direction)

Therefore, the speed of the block after the collision is 1.67 m/s, moving to the west.

2. To calculate the change in gravitational potential energy, we can use the equation:

Change in gravitational potential energy = mass * gravitational acceleration * change in height

Given:
Mass (m) = 55 kg
Change in height (Δh) = 370 m
Gravitational acceleration (g) = 9.8 m/s^2 (approximately)

Plugging in the values, we get:

Change in gravitational potential energy = 55 kg * 9.8 m/s^2 * 370 m

Now, we can calculate the answer:

Change in gravitational potential energy = 199,430 J

So, the correct answer is indeed 199,430 J. It seems that your initial calculation was correct.