# CBSE Class 9 Science, Motion: Important Questions & Preparation Tips

Try to get clear-cut difference between rest and motion

• Concept of reference point

• Concept of straight line motion

• Study the difference between distance and displacement (Very important)

• Which of the following is true for displacement?

(a) It cannot be zero.

(b) Its magnitude is greater than the distance travelled by the object.

• Meanings of uniform and non-uniform motions and it is must to know real life examples for both motions

• Practice the numerical on distance-time concept

• Calculation of average speed and average velocity. Difference between both velocities

• Units of speed and velocity

• What is the speed of sound in air?

• The odometer of a car reads 2000 km at the start of a trip and 2400 km at the end of the trip. If the trip took 8 hrs, calculate the average speed of the car in km hñ1 and m sñ1.

• Concept of acceleration with examples

• Concept of uniform and non-uniform acceleration and graphical representation for both

• A train starting from a railway station and moving with uniform acceleration attains a speed 40 km hñ1 in 10 minutes. Find its acceleration.

• Shapes of graphs for uniform and non-uniform speed and velocity

• How you can determine the distance moved by a car from its velocity-time graph.

• When an object moves along a straight line with uniform acceleration then how many equations are being used to relate its velocity, acceleration during motion and the distance covered by it in a certain time interval.

• Have a good command over example problems

• The guidelines or conditions to be used the equations of motion like when the signs will be negative and meaning of every quantity used in the same

• What is the quantity which is measured by the area occupied below the velocity-time graph?

• Practice the Velocity-time graph to obtain the equations of motion

• A stone is thrown in a vertically upward direction with a velocity of 5 m s^{-1}. If the acceleration of the stone during its motion is 10 m sñ2 in the downward direction, what will be the height attained by the stone and how much time will it take to reach there?

• Concept of uniform circular motion

• Formula of velocity of an object running on a circular path and either this motion is accelerated or non-accelerated.

• If a person is moving on a hexagonal path, pentagonal path, or an octagonal path, then what type of motion he is trying to approach finally

• An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth.

**CBSE Class 9 Science: Important Questions & Preparation Tips**

**Important questions:**

Q. The SI unit of retardation is:

1. ms-1

2. ms-2

3. ms2

4. m

Q. Acceleration is vector or scalar quantity

Q. What information you get from the equation given below:

Q. Study the above equations for free fall motion

Q. A car accelerates at 1.5 m/s2 on a straight road. How much is the increase in velocity in the next 6 seconds?

Q. Pick the correct statement for a scalar quantity:

1. Magnitude only

2. Direction only

3. Both magnitude and direction

4. None of these

Q. State two differences between speed and velocity

Q. Give two examples of uniform and non-uniform motion

**CBSE Class 9 Mathematics and Science Tips and Strategies**

**CBSE Class 9 Important Questions & Preparation Tips: Mathematics**

**If you have any Question/Point on the above information, please ask/discuss it in the** **CBSE Group.**