Assignment
Class 7
Subject – science
Ch. Motion and Time
Q1. MCQs.
A) A student draws a distance – time graph for a moving scooter and finds that a section of the graph is a horizontal line parallel to the time axis. Which of the following conclusion is correct about this section of the graph?
i) The scooter has uniform speed in this section.
ii) The distance travelled by the scooter is the maximum in this section.
iii) The distance travelled by the scooter is zero in this section.
iv) The distance travelled by the scooter is minimum in this section.
B) The SI unit of speed is
i) Km/h
ii) Cm/s
iii) m/s
iv) km/s
C) The speed of a moving object is determined to be 0.06 m/s. this speed is equal to
i) 2.16 km/h
ii) 1.08km/h
iii) 0.216 km/h
iv) 0.0216 km/h
D) When the amplitude of vibrations of a simple pendulum is increased, then its time period :
i) Decreases
ii) Increases
iii) Remains the same
iv) First increases and then decreases
Q2. Very short answer questions:
a) Define speed. What is the SI unit of speed?
b) What is an odometer?
c) What is periodic motion? Give examples of periodic motion.
d) What do we observe to assign whether a body is moving slow or fast?
e) Define a simple pendulum.
Q3. Answer the following;
a) Differentiate between uniform and non – uniform motion.
b) What is distance – time graph? Write its advantages.
c) How time is measured using periodic motion?
d) How was time measured when pendulum clock was not invented?
Q4. Numerical questions:
a) A bus travelled the first 40 km of a journey in one hour and the next 60 km in the next one hour. Calculate the speed of the bus.
b) A person swims 120 m in a minute. What is his speed in km/h and m/s? How much time will he take to swim a distance of 45 m? With the above speed how much distance will he cover in 50 seconds?
c) If a car is moving with the speed of 50 m/s, how much distance will it cover in 2 minutes?
d) In an experiment to measure the time – period of a simple pendulum, the time for 20 complete oscillations was found to be 36 seconds. What is the time – period of this pendulum?
e) How much distance will a car cover in 20 seconds when moving with a speed of 72 km/h?
f) The distance travelled by a car at various time intervals are as follows:
Distance: (m) 0 5 10 15 20 25
Time : (s) 0 2 4 6 8 10
(i) Draw a distance – time graph for the car.
(ii) What is the nature of motion of the car?
Answers
Answer:
Inclined Plane Simple Machine Examples at Home
ladder.
sidewalk curb ramp.
slanted roof.
slide.
A student draws a distance – time graph for a moving scooter and finds that a section of the graph is a horizontal line parallel to the time axis. Which of the following conclusion is correct about this section of the graph
Explanation:
a moving scooter and finds that a section of the graph is a horizontal line parallel to the time axis. Which of the following conclusion is correct about this section of the graph?
i) The scooter has uniform speed in this section.
ii) The distance travelled by the scooter is the maximum in this section.
iii) The distance travelled by the scooter is zero in this section.
iv) The distance travelled by the scooter is minimum in this section.
B) The SI unit of speed is
i) Km/h
ii) Cm/s
iii) m/s
iv) km/s
C) The speed of a moving object is determined to be 0.06 m/s. this speed is equal to
i) 2.16 km/h
ii) 1.08km/h
iii) 0.216 km/h
iv) 0.0216 km/h
D) When the amplitude of vibrations of a simple pendulum is increased, then its time period :
i) Decreases
ii) Increases
iii) Remains the same
iv) First increases and then decreases
Q2. Very short answer questions:
a) Define speed. What is the SI unit of speed?
b) What is an odometer?
c) What is periodic motion? Give examples of periodic motion.
d) What do we observe to assign whether a body is moving slow or fast?
e) Define a simple pendulum.
Q3. Answer the following;
a) Differentiate between uniform and non – uniform motion.
b) What is distance – time graph? Write its advantages.
c) How time is measured using periodic motion?
d) How was time measured when pendulum clock was not invented?
Q4. Numerical questions:
a) A bus travelled the first 40 km of a journey in one hour and the next 60 km in the next one hour. Calculate the speed of the bus.
b) A person swims 120 m in a minute. What is his speed in km/h and m/s? How much time will he take to swim a distance of 45 m? With the above speed how much distance will he cover in 50 seconds?
Answer:
question no. 1 answer is ( i )