contestada

A particle experiences constant acceleration for 20 seconds

after starting from rest. If it travels a distance s1 in the first

10 seconds and distance s2 in the next 10 seconds then

a. s2 = s1

b. s2 = 2s1

c. s2 = 3s1

d. s2 = 4s1

Why?​

Respuesta :

Answer:

The correct answer is D. s₂=4s₁

Explanation:

The distance of a particle is given by:

[tex]s=s_{0}+v_{0} t + \frac{1}{2} a t^{2}[/tex]

where

s₀ is the initial position when t=0

v₀ is the initial speed when t=0

a is the constant acceleration

t is the time in seconds

Then, the position s₁ is given by:

[tex] s_{1} = s_{0}+v_{0} t_{1} + \frac{1}{2} a (t_{1})^{2} [/tex]

As the particle starts from rest v₀=0 and we consider s₀=0, s₁ will be:

[tex] s_{1}= \frac{1}{2} a (t_{1})^{2} [/tex]

Furthermore, the position s₂ is:

[tex] s_{2}= \frac{1}{2} a (t_{2})^{2} [/tex]

In this case t₁=10 s and t₂=20 s (10 seconds later). In other words t₂=2t₁.

We replace the value of  t₂ in the second equation (s₂):

[tex] s_{2}= \frac{1}{2} a (t_{2})^{2} \\ s_{2}= \frac{1}{2} a (2t_{1})^{2} \\ s_{2} = \frac{1}{2} a 2^{2}(t_{1})^{2} \\ s_{2} = \frac{1}{2} a 4 t_{1}^{2}  [/tex]

Finally, we divide s₂ by s₁ to get the ratio:

[tex] \frac{s_2}{s_1} =\frac{\frac{1}{2}a4t_{1}^{2} }{\frac{1}{2}at_{1}^{2}} =4 [/tex]

[tex]\frac{s_2}{s_1}=4 \\  s_{2} = 4 s_{1}[/tex]