Advertisements
Advertisements
प्रश्न
A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate
- the maximum height to which it rises.
- the total time it takes to return to the surface of the earth.
Advertisements
उत्तर
i. Initial velocity = 49m/s
Final velocity at maximum height = 0
g = −9.8m/s2 since the ball is moving in the opposite direction
Let the maximum height = h
Third equation of motion
v2 = u2 + 2gh
02 = (49)2 + 2x (−9.8) × h
2401 = 2 × 9.8h
122.5m = h
ii. Let the time taken to reach the maximum height = t
The first equation of motion
v = u + gt
0 = 49 + (−9.8) × t
49 = 9.8 × t
t = `49/9.8`
t = 5s
Time taken to reach maximum height = 5s
Total time taken by the ball to reach back to the earth 5 + 5 = 10s
APPEARS IN
संबंधित प्रश्न
During a free fall, will heavier objects accelerate more than lighter ones ?
Explain why, if a stone held in our hand is released, it falls towards the earth.
Explain why, the tip of a sewing needle is sharp.
An object falling freely from rest reaches ground in 2 s. If acceleration due to gravity is 9.8 m s-2, then the velocity of object on reaching the ground will be
What is the acceleration due to gravity?
State whether the below statement is True or False.
Neglecting air resistance, a body falling freely near the earth's surface has a constant acceleration.
Write scientific reason.
When we drop a feather and a stone at the same time from a height the stone reach the earth faster than a feather.
The mass of planet ‘X” is four times that of the earth and its radius is double the radius of the earth. The escape velocity of a body from the earth is 11.2 × 103 m/s. Find the escape velocity of a body from the planet 'X’.
Calculate the escape velocity on the surface of the moon given the mass and radius of the moon to be 7.34 × 1022 kg and 1.74 × 106 m respectively.
(Given: G = 6.67 × 10-11 Nm2/kg2)
When is free fall possible?
