physics problem plz help?

Question

An object starts at time t = 0 with a velocity of v0 = +3 m/s and undergoes a constant acceleration of a = -16 m/s2.

a) At what time does the speed of the object reach zero?
b) How far from its starting (t = 0) position is the object at time t1?
c) At what time does the object again pass through the starting (t = 0) position?
d) If the object had initially been moving twice as fast (6 m/s), how far would it have gone before its velocity reached zero?
e) Suppose a second object begins moving with a constant speed of v = 3 m/s in the same direction from the same location at the same time as the object in part (d). At what time do the paths of these two objects once again cross?

Answer 1

a) The speed (v) of the object is v = 3 - 16t
Just set v = 0 and solve for t. t = 3/16 sec

b) d = v0(t) + (1/2) at^2
therefore d = 3(1) + (1/2) (-16) = 3 -8 = (-5) m

for c), set d=0 and solve for t

Answer 2

Let s = distance, F = force, m = mass, a = acceleration, v = velocity, v0 = initial velocity, v1 velocity at t1, v(t) = velocity at time t, vf = final velocity, t = time, t0 equal initial time, t1 equal time 1, etc..

Hints: Acceleration is + if it acts in the direction of initial motion, - if it acts in the direction against initial motion.
s = v0*t+at²/2
v = v0+at
vf² = v0² + 2sa
F = ma and you can't push on a rope

This is why you learned (were supposed to learn) algebra. And if you're having trouble with this, God help you when you get to 2 dimensional motion.


Doug

Answer 3

??? What's your problem here? That is simple maths !!

Besides, a constant acceleration of 16 m/s², no matter whether positive or negative, is impossible. Nothing on earth accelerates that fast neither way ... Think it over, man, this is more than 1.5 times the earth's gravity...

But other than this fact, in theory, it is just simple maths.

Answer 4

i can respond to one in all your questions. a million) Water isn't densest at 4* Celsius. enable me clarify myself. while the different element / liquid is cooled, its density continuously decreases because of the fact the temperature is diminished. even nonetheless this would not persist with on water. while water is cooled till at last 4* Celsius, its exhibits decrease in density yet while the temperature is introduced everywhere between 4* Celsius - 0* Celsius, that's density somewhat will enhance. it fairly is often used as anomalous expansion of water. So in international places that have temperature below 0* Celsius, water freezes to type snow. additionally the snow is way less dense and would not dissolve in water. extremely it evaporates. as a result snowstorm is obtainable in international places having temperature below 0* Celsius. i visit objective to seek for an answer on your 2nd question. -- Broledh

Answer 5

the given Q is wrong bcos the acceleration =
-16m/s^2 cannot be greater than the forward velocity

also it gives a negative distance which is not possible