Could someone please tell me HOW to solve these physics problems?

Question

A radio controlled toy car increases speed over a distance of 15.2 m. If the car starts at rest and has a final speed of 0.76m/s, what is the magnitude of it's acceleration?

A barge moving with a speed of 1.00m/s increases speed uniformly, so that in 30.0s it has traveled 60.2m. What is the magnitude of the barge's acceleration?

Answer 1

toy car:
given d = 15.2 m, v1 = 0 m/s , v2 = 0.76 m/s and you are looking for the acceleration...
just use the formula...

a = v2^2 - v1^2 / 2d
just substitute and solve...

barge:
given v = 1.00 m/s, t = 30.0 s, d = 60.2 m, and you are looking for the acceleration..
use the formula

d = vt + 1/2 a*t^2
or
a = 2(d - vt) / t^2
again, just substitute and solve...

Answer 2

CAR:- v² - u² = 2 a s
a = (v² - u²) / 2s = {(.76)² - 0²} / 2 * 15.2
a = (.5776 ) / 30.4 = .019 m / sec² ...Ans
. . . . . . . . =======================

BARGE:- s =ut + ½ at²
s = 60.2 m
u = 1 m/s
t = 30 sec

60.2 = 1 * 30 + ½ a 30²
60.2 = 30 + 450 a
60.2 - 30 = 450a
30.2 = 450 a
a = 30.2 / 450 = .0671 m/sec²
. . . . . . . . . .==============

Answer 3

CAR
v² - u² = 2 a s
v² = 2 a s since u = 0
a = v² / 2a
a = 0 .76² / 2 * 15.2
a =0.019 m / sec².
=======================
BARGE
Distance = average velocity x time
S = [u +v] * t/2
[u +v] = 2S/t = 2*60.2 / 30 = 4.01 m/s
v = 4.01 - u = 4.01 - 1 = 3.01m/s
v-u = 3.01 - 1= 2.01
a = [v -u] /t= 2.01 /30 =0.067 m/^2
=============================

Answer 4

acceleration = change in speed / time = (v1 - v0)/t

so you need to find those items

v0 = 0
v1 = 0.76

find t
average speed = v1/2 = 0.38
t = 15.2/0.38 = 40

acceleration = 0.76/40 = 0.019 m/s/s

second

v0 = 1
average =60.2/30 = (change + 1 + 1)/2
change = 2 x (60.2/30 - 1) = 2 x 30.2/30 = 60.4/30

acceleration = (60.4/30)/30 = 0.06711 m/s/s

Answer 5

v^2 - u^2 = 2as
u = initial velocity = zero
v= final velocity = 0.76m/s
s= distance covered = 15.2m

So, find a..... calculate yourself

s=ut+1/2 a t^2
u = initial velocity = 1.00m/s
s= distance covered =60.2m
t= time taken = 30.0s

So, find a..... calculate yourself