physics help!!!!

mkelly1992

physics help!!!!
Have 24 probs on this physics assignment, stuck on 2 though, only have one attempt left to submit them before I can't get credit
Chapter 02, Problem 36 GO


1)Two soccer players start from rest, 38 m apart. They run directly toward each other, both players accelerating. The first player’s acceleration has a magnitude of 0.46 m/s2. The second player’s acceleration has a magnitude of 0.50 m/s2. (a) How much time passes before the players collide? (b) At the instant they collide, how far has the first player run?

(a)
(b)

2)Chapter 02, Problem 04

You step onto a hot beach with your bare feet. A nerve impulse, generated in your foot, travels through your nervous system at an average speed of 177 m/s. How much time does it take for the impulse, which travels a distance of 1.53 m, to reach your brain?

ChippingSodbury

mkelly1992 wrote: »

physics help!!!!
Have 24 probs on this physics assignment, stuck on 2 though, only have one attempt left to submit them before I can't get credit
Chapter 02, Problem 36 GO


1)Two soccer players start from rest, 38 m apart. They run directly toward each other, both players accelerating. The first player’s acceleration has a magnitude of 0.46 m/s2. The second player’s acceleration has a magnitude of 0.50 m/s2. (a) How much time passes before the players collide? (b) At the instant they collide, how far has the first player run?

s = ut + 1/2at^2
t = same for both players (they start and finish at the same time)
player1 s + player2 s = 38m (player1 runs 38m - player2 s)
shoud be able to work it out from there
(a)
(b)

2)Chapter 02, Problem 04

You step onto a hot beach with your bare feet. A nerve impulse, generated in your foot, travels through your nervous system at an average speed of 177 m/s. How much time does it take for the impulse, which travels a distance of 1.53 m, to reach your brain?
You must be overcomplicating this one! Work out how long it takes to go 1 metre (hint: look at the Units, you've got m/s, you want s/m), then multiply by 1.53

See above for hints...

FISMA

mkelly1992 wrote: »

1)Two soccer players start from rest, 38 m apart. They run directly toward each other, both players accelerating. The first player’s acceleration has a magnitude of 0.46 m/s2. The second player’s acceleration has a magnitude of 0.50 m/s2. (a) How much time passes before the players collide? (b) At the instant they collide, how far has the first player run?

Since both players have a constant acceleration you can use the kinematic equations (keq).

The players collide when they are co-located, that's the key here. But you want the time of this occurrence for a) not where it occurs.

Look's like you're going to use one particular keq twice.

Set up one keq for player 1 and the same for player 2. Set eq 1 equal to the final position. Set eq 2 equal to the final position. Since xf for eq1 is xf for eq2, you can set eq 1 = eq 2 and solve for time.

Once you have time, just plug into an equation for either player and solve for xf.

citrus burst

mkelly1992 wrote: »

physics help!!!!
Have 24 probs on this physics assignment, stuck on 2 though, only have one attempt left to submit them before I can't get credit
Chapter 02, Problem 36 GO


1)Two soccer players start from rest, x = 38 m apart. They run directly toward each other, both players accelerating. The first player’s acceleration has a magnitude of a1 = 0.46 m/s2. The second player’s acceleration has a magnitude of a2 = - 0.50 m/s2. (a) How much time passes before the players collide? (b) At the instant they collide, how far has the first player run?

(a)
(b)

2)Chapter 02, Problem 04

You step onto a hot beach with your bare feet. A nerve impulse, generated in your foot, travels through your nervous system at an average speed of v = 177 m/s. How much time does it take for the impulse, find t which travels a distance of x = 1.53 m, to reach your brain?

made your problems easier, especially the 2nd