Question

I just wanna get my answer checked:

Answer 1

The height at time t (s) of a weight, oscillating up and down at the end of a spring is given below.
s(t) = 400 + 90sin(t)

Answer 2

a) Find the velocity at t = π/3 s.
b) Find the acceleration at t = π/3 s

Answer 3

so for a) my equation i had was 90sin(t)
and b) 90cos(t)

Answer 4

wondering if those are right.

Answer 5

for velocity, u differentiate once, for acceleration, u differentiate twice.

Answer 6

so NO

Answer 7

first derivative of s(t) = 400 + 90sin(t) is ??

Answer 8

90cos(t) ??

Answer 9

yes, thats your velocity

Answer 10

and acceleration ?

Answer 11

-90sin(t)

Answer 12

thats correct also :)

Answer 13

now just put t values

Answer 14

so the answers are:
A) 45
b) -45 sqrt3

???

Answer 15

yes.

Answer 16

woo hoooo. : )