Problems with Uniformly Straight Motion and Uniform Changes in Straight Motion Accompanied by Discussion.

 This time the admin shares questions about uniform straight motion and uniformly changing straight motion along with their explanations. Adapted to the latest curriculum, namely the K13 curriculum. This question can be used as a reference for the teacher in teaching. And can be used as learning material for friends.

Answer the following questions with the most correct answer.

1. A ball is rolling across a highway with a speed of 6 m/s. if the time it takes the ball from the top of the highway is 2 seconds. How wide is the highway?

Discussion :

Okay, this time it's about a ball rolling on the highway. From the problem above, we can identify that the motion of the ball is a uniform straight motion. Why is that? Because the problem only consists of two values, namely the magnitude of speed and distance. There is no initial velocity nor is there any acceleration. Then it can be solved as follows:

Is known :

Speed ​​: 6m/s

Time: 2 sec

Wanted : distance(s)...?

Answer :

The formula for distance = speed multiplied by time.

S = v x t

S = 6 x 2 = 12 m

So the width of the road is 12 m

2. A car travels a distance of 60 km. In 12 minutes what is the speed of the car.

Discussion :

Problem number two above is the same as problem number one, except that we need to find the velocity equation. So the answer is as follows:

Is known :

Distance(s) = 60 km = 60 x 1000 = 60,000 m

Time (t) = 12 minutes = 12 x 60 = 720 m

Asked the speed of the object...?

Answer :

To find the speed, divide the distance by the time

v = s/t = 60,000/720 = 83.33 m/s

3. What is meant by uniform linear motion?

Discussion :

Uniform motion is the motion of an object in a straight line at a constant speed.

4. A car travels 30 km/hr in half an hour. If the car travels a distance of 45 km. How much time does the car take?

Discussion :

For question number 4 we will find the time it takes to cover a distance of 45 km at a speed of 30 km/hour. So the equation is as follows:

Is known :

Distance(s) = 45 km

Speed ​​= 30 km/hour

Asked: .....?

Answer :

S = v x t

t = s/v

t = 45 / 30 = 1.5 hours

5.Name some examples of objects that experience uniform motion in a straight line in life?

Discussion :

The motion of a car without increasing acceleration, the motion of astronauts in space, and the motion of objects in a vacuum.

6. Look at the chart below

Based on the graph above, at what time the object is the distance traveled from the object is

Discussion :

From the graph above we will find the distance in the graph. We can know that the velocity and time in the graph are as follows:

Is known :

Speed ​​: 60m/s

Time: 4 s

Asked: distance ....?

Answer :

S = v x t

S = 60 x 4

S = 240 m

7. From graph number 6 above, if determine the distance of the object at t 5 seconds

Discussion :

Question no 7 above is the same as question number 6, which is to find the distance of the object then

Is known :

Speed ​​: 70m/s

Time: 5 s

Asked: distance ....?

Answer :

S = v x t

S = 70 x 5

S = 350 m

8. Pay attention to the following picture

From the graph above, determine the distance traveled by the object. If the acceleration of the object is 2 s

Discussion :

From the graph above, it can be seen the value of the following quantities:

Is known :

Initial speed : 20 m/s

The speed after t second is 70 m/s

The object's acceleration is a 2 m/s²

Asked:

The question above is

Determine the distance from the object

Answers: 

Asked the distance traveled (s) in 5 seconds

To solve the above problem, we can use the following equation:

Vt2 = Vo2 + 2as

702 =202 + 2(2)s

4900 = 400 + 4s

4900 - 400 = 4s

4500 = 4s

S = 4500/4

S = 1125 m

Then the distance traveled from the car is 1.125 m = 1.125 km

9. What is meant by uniformly changing straight motion

Discussion :

Uniform linear motion is motion in a straight line in a straight line with a speed that increases regularly with time. And has a constant speed.

10.A bicycle is initially moving at a speed of 20 km/h after that the car is on the gas and has an acceleration of 5 ^m/_s². what is the final velocity in 6 seconds.

Discussion :

The problem above is a matter of uniform motion in a straight line. That is motion that has a constant acceleration. It is proved that there is acceleration. Then the problem can be solved with the following equation:

Is known :

Speed ​​= 20 km/h = 20 1000/3600 = 20/3.6

Acceleration = 5 ^m/_s²

Time = 6 s

Wanted: speed after 6 seconds...?

Answer :

Vt = vo + at

Vt = 20/3.6 + 5 (6)

Vt = 20 /3.6+ 30

Vt = 128/3.8 = 35.5556 = 36 m/s

11. Nisa drives a car with an acceleration of 20 m/s² Determine the time that has been taken by Nisa's car if the acceleration of Nisa's car is 12 s and the initial speed is 12 m/s.

Discussion :

Is known :

Acceleration of object : 20 m/s²

Time : 12 s

Speed ​​: 12 m/s

Asked:

The speed of the car in t seconds..?

Answer :

About

vt = vo + at

vt = 20 + (12).( 12)

vt = 164 m/s

12. Afgan rides a motorcycle with a speed of 20 m/s acceleration of 12 m/s2 Determine the time it will take Afgan if he has covered a distance of 64 m.

13. Look at the graphic image below

From the picture, at what time does the car accelerate?

Discussion:

From the picture above, it can be understood that the car experienced a significant increase in speed at 0

14. Name examples of everyday objects that experience uniform motion in a straight line.

Discussion:

Cars in motion and on gas

Train

Airplanes and others

15. It is known that a car can travel 45 m at a speed of 20 m/s then the car accelerates with an acceleration of 10 m/s². what is the final speed of the car.

Discussion :

The problem above serves to find the final velocity as follows:

Is known :

S = 45 m

vo = 20 m/s

a = 10 m/s2

Asked:

The speed ​​at t second..?

Answer :

To find the speed at time t second then as follows:

v^m/_t² =v ^m/_o² + 2 a s v^m/_t² =20² + 2 20 . 45 v^m/_t² =400 + 1800 v^m/_t² =2200 v_t = 46,904 m