# calc help

posted by .

the position function of a particle is given by
s=t^3–4t^2–7t t>=0

where s is measured in meters and t in seconds. When does the particle reach a velocity of 10 m/s?

• calc help -

Take the derivative:

v=3t^2 -8t -7

put v=10 and rearrange it to have a quadratic in standard format, solve the quadratic with the quadratic formula.

• calc help -

i got 1.39 and -4.06 but i still got it wrong

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### Calculus please help

I have 3 calc problems that i have not been able to do please help me... i've been on here yesterday as well but no one was able to assist me with these particular ones... 1. If f(x)=5x^3–2/x-4 find f'(x)____ what i got was (4x^2+7x-12)/x^8 …
2. ### Calculus- To Reiney

I have 3 calc problems that i have not been able to do please help me... i've been on here yesterday as well but no one was able to assist me with these particular ones... 1. If f(x)=5x^3–2/x^4 find f'(x)____ what i got was (4x^2+7x-12)/x^8 …
3. ### calculus

a particle moves along a number line measured in cm so that its position at time t sec is given by s=72/(t+2) +k, k is a constant and t>=0 seconds. (a) Find the instantaneous velocity of the particle at t=4 seconds (b) Find the …
4. ### Calculus

The position in meters of a particle is given by f(t)= 14t-3t^2, where t is measured in seconds. a) Evaluate f'(2) and interpret the results. This is how I solved this. f'(t)=14-6t= 2(7-3t) f'(2)=2(7-3(2))= 2 This means the velocity …
5. ### Calculus

A particle moves along a horizontal line so that at any time t its position is given by x(t)=cost-t. Time is measured in seconds and x is measured in meters. a.) Find the velocity as a function t. Use your answer to determine the velocity …
6. ### Calculus

The displacement (in meters) of a particle moving in a straight line is given by s=2t^3 where is measured in seconds. Find the average velocity of the particle over the time interval [10,13]. the average velocity is 798 What is the …
7. ### Calculus

The position of a particle moving on a horizontal line is given by s(t)=2t^3-15t^2+24t-5, where s is measured in feet and t in seconds. a: What is the initial position of the particle?
8. ### calculus

velocity of a particle- the displacement s (in meters) of a particle moving in a straight line is given by the equation of motion s=4t^3+6t+2, where t is measured in seconds. Find the velocity of the particle s at times t=a t=1 t=2 …
9. ### MATH

The position function of a particle is given by s(t) = t^{3}-3t^{2}-7t, t\ge 0 where s is measured in meters and t in seconds. When does the particle reach a velocity of 20 m/s?
10. ### calc

Given the position function, s of t equals negative t cubed divided by 3 plus 13 times t squared divided by 2 minus 30 times t, between t = 0 and t = 9, where s is given in feet and t is measured in seconds, find the interval in seconds …

More Similar Questions