Question

Scientists are experimenting with a king of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 5.0kg projectile from rest to speed of 4.0 x 10^3 m / s. The net force accelerating the projectile is 4.9 x 10^5N. How much time is required for the projectile to come up to speed?

Answer 1

@hartnn

Answer 2

we have Force and Mass,
so we can get acceleration

The famous formula
F= Ma

Answer 3

then we can use the kinematic equation

v = u+ at
to get the time

Answer 4

So we'll only be using 4.9 x 10^5 and 5.0 kg?

Answer 5

yep

4.9 * 10^5 = 5*a

Answer 6

we'll be using this:
"rest to speed of 4.0 x 10^3 m / s"
to get the time

initial velocity = u = rest = 0 speed

Answer 7

This is deep man! :P, It's been long since I did this kind of math :)

Answer 8

me too Sandeep :P
I am googling the formulae ':)

Answer 9

Okay so for 4.9 * 10^5 = 5*a we have:
490,000 = 5a
a= 98000

Answer 10

@hartnn hehe +1

Answer 11

yes,
and now use the formula

v = u+at

"rest to speed of 4.0 x 10^3 m / s"

initial velocity = u = rest = 0 speed
final velocity = v = 4*10^3

a = 98000

find t

Answer 12

\[4000 = 0 + 98000t\]
\[4000 = 98000t\]

Answer 13

t = 0.041

Answer 14

seems correct :)

Answer 15

So that's my answer?

Answer 16

in seconds, yes

Answer 17

Thanks!! Now last question.