# Homework Help: Position and acceleration

1. Apr 15, 2017

### mike32

1. The problem statement, all variables and given/known data
All numerical constants are in the appropriate units, so that R (t) in units of meters, and a = 3.1 sec-1.

What is acceleration size (in meters per second ^ 2) t = 1 / 1.1 sec?

Note: When calculating sin (at), make sure the computer is in radian mode.

2. Relevant equations
R(t)= 8.4sin(at) +(3.1e^(-7t)) +6.9t^3

3. The attempt at a solution
Couldn't get to a solution

2. Apr 15, 2017

### Nidum

Please try to explain this problem more clearly . Post the complete original wording of the problem as given to you if possible

3. Apr 15, 2017

### mike32

R (t) in meters and a= 3.1 sec^-1

What is its acceleration (m/s^2) in t = 1 / 1.1 seconds?

4. Apr 15, 2017

### haruspex

How do you go from an expression for position to one for acceleration?
Do you mean literally $\frac {1}{1.1}$ seconds? That is a very odd way to specify the time.

Last edited: Apr 15, 2017
5. Apr 15, 2017

### mike32

ok. but this is data in question.

6. Apr 15, 2017

### haruspex

Ok, so answer my first question.

7. Apr 15, 2017

### mike32

Have to cut twice the equation and put t