Question

C. State whether the following statements are true or false.
1. A body in a circular path has a constant velocity.
2. A ball thrown up reaches a height of 3 m and returns back to the hands of the thrower. Its
displacement is 6 m.
3. Displacement is always equal to distance travelled.
4. A body with constant velocity has no acceleration.
5. If the time period of a simple pendulum is 2 s, its frequency is 5 Hz.
pls answer it fast​

Answer 1

The ball returns to the ground after 6 seconds.
Thus the time taken by the ball to reach to the maximum height (h) is 3 seconds i.e t=3 s
Let the velocity with which it is thrown up be u

(a). For upward motion,
v=u+at
∴ 0=u+(−10)×3
⟹u=30 m/s

(b). The maximum height reached by the ball
h=ut+
2
1
​
at
2

h=30×3+
2
1
​
(−10)×3
2

h=45 m

(c). After 3 second, it starts to fall down.
Let the distance by which it fall in 1 s be d
d=0+
2
1
​
at
′2
where t
′
=1 s
d=
2
1
​
×10×(1)
2
=5 m
∴ Its height above the ground, h
′
=45−5=40 m
Hence after 4 s, the ball is at a height of 40 m above the ground.

Answer 2

Answer:

1.False

--- because velocity is vector quantity,so when direction changes even if a magnitude is same,it velocity change.

2.False

--- as per the definition displacement is the the minimum distance between the initial and find position but in this case the ball come back to the hand of thrower which was initial position that's why net displacement is zero.

3.False

--- displacement can be equal or less then the distance.

4.True

5.False

--- frequency=1/ time period

frequency=1/2

=0.5Hz