#### Question

# Simple Physics Questions?

1- Marissa's car accelerates uniformly at a rate of +2.60 2 .

m/s

How long does it take for Marissa's car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~…

3. Nathan accelerates his skateboard uniformly along a straight path from rest to 12.5 m/s in 2.5s.

a. What is Nathan's acceleration?

b. What is Nathan's displacement during this time interval?

c. What is Nathan's this time average velocity during this time interval?

#### Answer

1. a = 2.60 m/s2 [I'm guessing that's what you mean for the acceleration]

v(i) = 24.6 m/s

v(f) = 26.8 m/s

t = ?

v(f) = v(i) + at

t = [v(f) - v(i)] / a

t = [26.8 - 24.6] / 2.60

t = 0.846 s

3. v(i) = rest = 0 m/s

v(f) = 12.5 m/s

t = 2.5 s

(a) a = [v(f) - v(i)] / t

a = [12.5 - 0] / 2.5

a = 5 m/s2

(b) s = v(i)t + (1/2)at2

s = 0 + (1/2) * 5 * 2.52

s = 15.625 m

(c) average velocity = total displacement / time taken

= 15.625/2.5

= 6.25 m/s