Question

aunched from the ground a coin vertically upwards at a speed of 15 m / s, at the same instant and from a height of 40m, are projected vertically downwards a stone with a speed of 5 m / s is calculated up to the crossing. Is the currency is rising or falling at that instant? Where is the money lost when the maximum height reached if?

Answer 1

launched**

Answer 2

@sami-21

Answer 3

i think coin has lost in air

Answer 4

means?

Answer 5

hmmm

Answer 6

ok lets do this
for coin
\[x_{1}=15t-0.5 (g)(t^2)\]
for stone
\[x_{2}=40-(5t+0.5(g)t^2\]
using g=9.8m/sec^2
set
\[x_{1}=x_{2}\]
\[15t-4.90t^2=40-5t+4.90t^2\]
solve for t
( i hope you are familiar with solving Quadratic equations)
t=2 sec
(neglect the other root of quadratic equation)
using first equation time for coin can be calculated will compare these two to decide whether coin is moving downward or upward .
vf=vi-gt
but vf=0
t=vi/g=15/9.8=1.533

since
\[1.533<2\]
so coin is \[falling\] (moving downward at that time.

now
Where is the money lost when the maximum height ?

for maximum height i will use third equation .
\[2(-g)(h)=v^2_{f}-v^2_{i}\]
vf=0 here
\[h=\frac{v^2_{i}}{2g}\]
\[h=\frac{15^2}{2(9.8)}=11.479m\]

i hope you got that .if need any help let me know .

Answer 7

@Muskan

Answer 8

this is projectile numericals. . .

Answer 9

@theyatin do not mind but i think it is not projectile motion. because it is simple one dimensional problem under gravity. while projectile is 2 dimensional.

Answer 10

jo formula use karty hain bare ajeeb hain meri book may nhi hain :((
2(−g)(h)=v2f−v2i like this

Answer 11

doesn't matters dear sami its projectile at angle 90'
still it is categorized under projectile motion. . .
everyting thrown up is projeted. . .

Answer 12

@Muskan this formula is just yjird equation of motion you know this formula
\[2as=v^2_{f}-v^2_{i}\]
for gravitation acceleration it changes to
\[2gs=v^2_{f}-v^2_{i}\]
i just used h instead of s and (-g) because moving upward so g will be negative
did u get that??

Answer 13

third*

Answer 14

quest :D

Answer 15

?