Telangana SCERT Class 7 Science Chapter 4 Solution – Motion and Time. Here in this post we provides Class 7 Science Motion and Time Telangana State Board Solution. Telangana State Board English Class VII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.
Telanagana State Board Class 7 Science Chapter 4 Motion and Time Solution:
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(1) State weather the following statements are true or false. Rewrite the wrong statement correctly.
(a) A body can be at rest and in motion at the same time in relation to the same set of surrounding.
Ans: – False
A body can be at rest in motion at the same time in relation to the different sets of surrounding.
(b) A passenger flying in an airplane is at rest with respect to the airport and moving with respect to the passengers.
Ans: – False
A passenger flying in an airplane is at rest with respect to the other passengers and moving with respect to the airport.
(c) The wheels of a train are in rotator motion as well as in translator motion, when it moves.
Ans: – True.
(2) John tied a stone to a string and whirled it around. What type of motion do you find there?
Ans: – IT is an example of rotator motion here the stone is in circular motion.
(3) What is common to the following? Motion of the propeller of a flying helicopter, the minute hand of a watch, the type of a cassette recorder.
(a) All are examples of translator motion.
(b) All are examples of oscillatory motion.
(c) All are examples of periodic motion.
And: – All are examples.
(4) Which of the following is not an oscillatory motion?
(a) Motion of the hammer of a electric bell.
(b) Motion of your hands while running.
(c) Motion of a child on a see-saw.
(d) Motion of a horse pulling a cart.
Ans: – (d) Motion of a horse pulling a cart. Because here is only one direction. Its not an oscillatory motion.
(5) Arun completed a 100 meter race is 16s. While karthik finished it in 13s. Who ran faster?
Ans: – Karthik ran faster because it’s speed is 13/s. But Arun’s speed is 16/s. So here we say that Karthik ran faster Arun ran slower.
(6) (1) A train runs from New Delhi to Hyderabad. It covers first distance of 420 km in 7hrs. And next distance of 360 km. In 6hrs.
(ii) Gopt takes part in a car race. He drives a distance of 70 km each in the first, Second and third hours.
Which of the following statements is true.
(a) I, is an example uniform motion and II is an example of non-uniform motion.
(b) I, is an example non-uniform motion and II is an example of uniform motion.
(c) I and II are examples of uniform motion.
(d) I and II are examples of non-uniform motion.
Ans: – I, is an example non-uniform motion and II is an example of uniform motion.
(7) Write the motion of different part of a bicycle while it is motion.
(a) The wheel
(b) The cycle
(c) The pedal with its arm.
(d) The movement of the feet pedalling.
(e) The movement of the rider along with the bicycle.
Ans: – (a) The wheel = Rotatory motion (Circular motion)
(b) The pedal with its arm = circular motion
(c) The pedal with its arm = circular motion.
(d) The movement of the feel pedalling = circular motion related to Rotatory motion.
(e) The movement of the rider along with the bicycle = Multiple and random motion.
(8) Which of the following statements is correct?
(a) The basic unit of time is second
(b) Every object’s motion is uniform
(c) Two cars move for 5 minutes and 2 minutes respectively. The second car is faster because it takes less time.
(d) The speed of a car is expressed in km/h.
Ans: – The correct statement is (a) the basic unit of time is second. As per SI, the standard unit of time is second.
(9) The basic unit of speed is
(a) km/min
(b) m/min
(c) km/h
(d) m/s
Ans: – m/s is the basic unit of speed.
(10) The correct relation between speed, distance and time is
(a) Speed = distance x time
(b) Speed = time/ distance
(c) Speed = distance / time
(d) Distance = speed / time
Ans: – Speed = distance / time
(11) The distance between two stations is 420 km. A train takes 4 hrs to cover this distance. Calculate the speed of the train.
Ans: – Distance = 240km, Time = 4 hrs.
Speed = distance travelled/ Time taken
= 240/4 km/h
= 60 km/h
Speed of the train is 60 km/h
(12) A traijn travels at a speed of 180 kmh. How far will it travel in 4 hours.
Ans: – speed = distance/ time
180 km/h = distance/ 4hrs
180 km x 4hrs = distance
Distance = 720 km
Or,
Speed given = 180 km/hr
Time = 4 hrs
We know, Distance = speed x time
= 180 km/hr x 4 hrs.
= 720 km
720 km for will it travel in 4 hours.
(13.) When do you say an object is in rotatory motion?
Ans. Rotatory motion can be defined as the motion of all particles of moving body follow a circular path with respect to a fixed centre or axis of rotation. That means the motion in which an object is moving about a fixed position.
For example the celling fan of a house. The centre of the fan which is fixed. Its position is not changing. Only the blades of a fan are changing their position continuously and moving in circular path around the fixed point.
(14) Can an object possess translatory and rotatory motion at the same time? Give an example.
Ans. Yes, it can possess both translatory and rotational motion at the same time.
Example: A vehicle wheel like car, bus etc.
Car moving in a straight line, its wheel move in rotational motion and car moves in a translatory motion.
(16.) In a sewing machine used by tailors, mention the type of motion of sewing machines parts when it runs.
a) the wheel
b) the needle
c) the cloth
Ans. In a sewing machine used by tailors sewing machine wheel is in rotational motion.Sewing machine needle has oscillatory (periodic) motion when it runs. When a sewing machine runs its needle gets up and down showing an motion.
The motion of the cloth in sewing machine is translatory motion.
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