guys solve 1 to 11 very necessary
Answers
Answer
1.Yes. An object that has moved through a distance can have zero displacement. Displacement is the shortest distance between the initial and the final position of an object. An object which has covered a distance can have zero displacement if it comes back to its starting point i.e., the initial position.
2.Consider the following situation. A man is walking along the boundary of a square park of side 20 m (as shown in the following figure). He starts walking from point A and after moving along all the sides of the park (AB, BC, CD, DA), he again comes back to the same point i.e., A.
In this case, the total distance covered by the man is 20 m + 20 m + 20 m + 20 m = 80 m. However, his displacement is zero because the shortest distance between his initial and final position is zero.
3.The magnitude of average velocity of an object is equal to its average speed if the object moves in a straight line in a particular direction.
4.The odometer of an automobile measures the distance travelled by a vehicle.
5.An object having uniform motion has a straight line path.
6.Time taken by the signal to reach the ground station from the spaceship
= 5 min = 5 × 60 = 300 s
Speed of the signal = 3 × 10∧8 m/s
Distance travelled = Speed × Time taken = 3 × 10∧8 × 300 = 9 × 10∧10 m
Hence, the distance of the spaceship from the ground station is 9 × 10∧10 m.
7.(i) A body is said to have uniform acceleration if it travels in a straight path in such a way that its velocity changes at a uniform rate, i.e., the velocity of a body increases or decreases by equal amounts in an equal interval of time.
ii) A body is said to have non-uniform acceleration if it travels in a straight path in such a way that its velocity changes at a non-uniform rate, i.e., the velocity of a body increases or decreases in unequal amounts in an equal interval of time.
8.Initial speed of the bus, u = 80 km/h
Final speed of the bus, v = 60 km/h
Time take to decrease the speed, t = 5 s
Acceleration, a=v-u/t= 16.66-22.22/5=-1.112m/s∧2
Here, the negative sign of acceleration indicates that the velocity of the car is decreasing.
9..Initial speed of the train, u = 0
Final speed of the bus, v = 40km/h
Time take to decrease the speed, t = 10*60 secs=600 secs
Acceleration, a=v-u/t= 16.66-22.22/600=-0.0185m/s∧2
10.The distance−time graph for uniform motion of an object is a straight line.
The distance−time graph for non-uniform motion of an object is a curved line.
11.When an object is at rest, its distance−time graph is a straight line parallel to the time axis.
see the attachment for understanding the solve of no.2
