Help please (20 pts) I think it's C

A car stops in 130 m. If it has an acceleration of -5 m/s2 what was the cars starting velocity?

Tatiana [17]

Answer:

We are given:

displacement (s) = 130 m

acceleration (a) = -5 m/s²

final velocity (v) = 0 m/s [the cars 'stops' in 130 m]

initial velocity (u) = u m/s

Solving for initial velocity:

From the third equation of motion:

v² - u² = 2as

replacing the variables

(0)² - (u)² = 2(-5)(130)

-u² = -1300

u² = 1300

u = √1300

u = 36 m/s

8 0

3 years ago

The SI unit for energy is Newton true or false

ipn [44]

Explanation:

false....it is joules

..........

6 0

2 years ago

A resistor has four colored stripes in the following order: orange, orange, brown and silver. What is the resistance of the resi

zubka84 [21]

Answer:

Resistance =330 Ω

Tolerance = 33 Ω

Explanation:

see attached resistor color code table

The first stripe is orange, which means the leftmost digit is a 3.

The second stripe is orange , which means the next digit is a 3.

The third stripe is brown. Since brown is 1, it means add one zero to the right of the first two digits.

The resistance is:

orange-orange-brown= 330 Ω

The tolerance is:

The fourth color band indicates the resistor's tolerance. Tolerance is the percentage of error in the resistor's resistance.

silver is 10%

A 330 Ω resistor has a silver tolerance band.

Tolerance = value of resistor x value of tolerance band

= 330 Ω x 10% = 33 Ω

330 Ω stated resistance +/- 33 Ω tolerance means that the resistor could range in actual value from as much as 363 Ω to as little as 297 Ω.

7 0

3 years ago

In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straightaway at 71.0 m/s. Th

elena55 [62]

Answer:

Thunderbird is 995.157 meters behind the Mercedes

Explanation:

It is given that all the cars were moving at a speed of 71 m/s when the driver of Thunderbird decided to take a pit stop and slows down for 250 m. She spent 5 seconds in the pit stop.

Here final velocity $v=0 \ m/s$

initial velocity $u= 71 m/s$ distance

Distance covered in the slowing down phase = $250 m$

$v^2-u^2=2as$

$a= \frac {(v^2-u^2)}{2s}$

$a = \frac {(0^2-71^2)}{(2 \times 250)}=-10.082 \ m/s^2$

$v=u+at$

$t= \frac {(v-u)}{a}$

$= \frac {(0-71)}{(-10.082)}=7.042 s$

$t_1=7.042 s$

The car is in the pit stop for 5s $t_2=5 s$

After restart it accelerates for 350 m to reach the earlier velocity 71 m/s

$a= \frac {(v^2-u^2)}{(2\times s)} = \frac{(71^2-0^2)}{(2 \times 370)} =6.81 \ m/s^2$

$v=u+at$

$t= \frac{(v-u)}{a}$

$t= \frac{(71-0)}{6.81}= 10.425 s$

$t_3=10.425 s$

total time= $t_1 +t_2+t_3=7.042+5+10.425=22.467 s$

Distance covered by the Mercedes Benz during this time is given by $s=vt=71 \times 22.467= 1595.157 m$

Distance covered by the Thunderbird during this time= $250+350=600 m$

Difference between distance covered by the Mercedes and Thunderbird

= $1595.157-600=995.157 m$

Thus the Mercedes is 995.157 m ahead of the Thunderbird.

6 0

3 years ago

If you double the frequency of a vibrating object, its period:

Furkat [3]

Answer:

becomes halved.

Explanation:

trust

8 0

3 years ago

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