Recent content by Amber430

Q: Displacement in a straight line is s= t^2- 5t + 15. What's the instantaneous velocity when t= 4? Equation: lim [f(a+h)-f(a)]/h as h approaches 0 I tried this problem and what I came up with for an idea of how to solve this makes absolutely no sense.

No, I was not using 3mg, just 3m. That's where I messed it up. It makes sense now, thank you so much!

A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius r. A passenger feels the seat of the car pushing upward on her with a force equal to three times her weight as she goes through the dip. If r = 22.0 m, how fast is the roller coaster traveling at the...

Ohhh okay! I get it now! I feel dumb now, Lol. Thank you so much

Okay I figured out frictional force, it is -789 J. I just forgot the negative sign. But for normal force, wouldn't it be the same as W (46 kg x 9.8= 451 N)? This is the value I plugged into the frictional force equation...but when I multiply 451 by 7 and plug in the answer for normal force it's...

A 46 kg box is being pushed a distance of 7.0 m across the floor by a force vector P whose magnitude is 148 N. The force vector P is parallel to the displacement of the box. The coefficient of kinetic friction is 0.25. Determine the work done on the box by each of the four forces that act on...

It would be 2a

But what is the acceleration?

V^2=Vo^2 + 2ax. But what is x? It isn't known.

The initial velocity remains the same. But the only other variable that is given is final velocity, which would not stay the same.

This problem really shouldn't be this difficult but for some reason I can't seem to find the answer. An arrow, starting from rest, leaves the bow with a speed of 26.0 m/s. If the average force exerted on the arrow by the bow were doubled, all else remaining the same, with what speed would the...

(a) How much time passes before the fish's speed doubles? (b) How much additional time would be required for the fish's speed to double again?

I can find either displacement or time. With either one I get 0. Vf= Vi + at --> 7.9= 7.9 + (0)t Vf^2= Vi^2 + 2ax --> 7.9^2= 7.9^2 + 2(0)x

That's what I did. I had Ax=0 m/s^2, Vix= 7.9 m/s, Ay= -9.8 and Viy= 0 m/s and when I plug them into any equation it is always zero

An eagle is flying horizontally at 7.9 m/s with a fish in its claws. It accidentally drops the fish. (a) How much time passes before the fish's speed doubles? (b) How much additional time would be required for the fish's speed to double again? Initial velocity in the x direction is...