Question

A car is moving with a velocity of 8m/s. If it accelerates at the rate 2m/s². Find out its velocity after 10s.​

Answer 1

Answer:

HOPESITHELPS

Explanation:

Let v,t

1

,t

2

be the maximum velocity attained, time for which car accelerated and the time for which car retarded respectively

⇒t

1

=(v−u)/a=(v−0)/2=v/2

⇒t

2

=(v−u)/a=(0−v)/(−4)=v/4

Now it is given that,

⇒t

1

+t

2

=3

⇒v/2+v/4=3

⇒v=4m/s

Hence correct answer is option C

Answer 2

$\huge\tt\red{❥}\tt\pink{A}\tt\blue{N}\tt\green{S}\tt\purple{W}\tt\orange{E}\tt\orange{R}\huge\tt\red{᭄}$

Given:-

A car is moving with a velocity of 8m/s. If it accelerates at the rate 2m/s². Find out its velocity after 10s.

To Find:-

Velocity after 10s.

Solution:-

A car is moving with the velocity of 8m/s and accelerates uniformly at 2 m/s2 for 10 seconds. What is the distance travelled by the car?

There are 2 methods to solve for the distance traveled by the car after it had accelerated by 2 m/s^2 for 10 s. The first method is to use v2^2 - v1^2 = 2ax where v1 = 8 m/s and v2 = 28 m/s. Finding for the value of x was easily done by the other responders.

The second method is to use the acceleration, time, and displacement formula where x is the displacement, a is the uniform acceleration and t = 10 seconds. The formula is x = v t - 1/2 a t^2 where v is the value of the final velocity from v = u + at.

Solving for the value of v after 10 s

v = u + at

v = 8 m/s + 2m/s^2 * 10 s

v = 8 m/s + 20 m/s = 28 m/s

Solving for the displacement x

x = vt - 1/2at^2

x = ((28 m/s) * 10 s) - (1/2(2 m/s^2)(10 s)^2)

x = 280 m - (1 m/s^2)(100 s^2)

x = 280 m - 100 m

x = 180 meters

The distance traveled by the car is 180 meters.