A ball is dropped from a height of 90m


Asked by admin @ in Physics viewed by 302 People


A ball is dropped from a height of 90 m on a floor. At each collision with the floor, the ball tosses one tenth of its speed. Plot the speed-time graph of its motion between t = 0 to 12 s.

Answered by admin @



It is given that Ball is dropped from a height = 90 m
Time interval, 0 to 12 sec
Initial velocity of the ball , u =0 m/s
Acceleration due to gravity , g = 9.8 m/s²
s = ut + 1/2 gt2
where, u = Initial velocity
g = Acceleration due to gravity
s = Distance covered
t = Time

⇒ 90 = 0 + 1/2 × 9.8 × t²
⇒ 90 = 4.9t²
⇒ t² = 900/49
∴ t = 30/7 = 4.28 s

From 1st equation of motion for freely falling body,
v = u + gt

Where u = 0, g = 9.8 m/s² and t = 4.28s

⇒ v = 0 + (9.8 ×4.28) ≈ 42 m/s

Bounce velocity of the ball, vb = 0.9v = 37.8 m/s

Time (t’) by the bouncing ball to reach maximum is given by,
v = vb – gt’
where,
v = Final velocity
vb = Bounce velocity
g = Acceleration due to gravity
t’ = Bouncing time
⇒ 0 = 37.84 – (9.8 ×t’)
∴ t’ = 3.86 s

Total time taken by the ball = t + t’ = 4.29 + 3.86 = 8.15 s

The will continue like this up to ball reach a static condition.

The graph obtained by the data is,

Similar Questions

A ball is dropped from a height of 12m

Asked by admin @ in Physics viewed by 331 persons

a ball is dropped from rest at a height of 12m.if it loses 25% of kinetic energy on striking the ground, what is the height to which it bounces?

A ball is dropped from a height of 20cm

Asked by admin @ in Physics viewed by 318 persons

a ball is dropped from a height of 20 cm. Ball rebounds to a height of 10 cm. Ball rebounds to a height of 10 cm. what is the loss …

A ball is dropped from a height of 5m

Asked by admin @ in Physics viewed by 290 persons

A ball is dropped from a height of 5m onto a sandy floor and penetrates the sand up to 10cm before coming to rest. Find the retardation of the ball …

A tennis ball dropped from a height of 2m

Asked by admin @ in Math viewed by 350 persons

A ball dropped from a height of 2m rebounds to a height of 1.5m after hitting the ground.Then the % of energy lost

A ball is dropped from a height of 10m

Asked by admin @ in Science viewed by 272 persons

a ball is dropped from a height of 10m.if energy of the ball reduces by 40% after striking the ground , how high can the ball bounce back? {g = …

A ball is dropped from a height of 10 m

Asked by maham237 @ in Mathematics viewed by 318 persons

Each time it bounces, it reaches 50 percent of its previous height. The total vertical distance the ball has traveled when it hits the ground the fifth time is ______ …

A body is dropped from a certain height

Asked by admin @ in Physics viewed by 279 persons

A body is dropped from certain height and another body is dropped from same height after 2 secs. What will be the separation between two bodies 4 secs after the …

A bullet is dropped from the same height

Asked by admin @ in Physics viewed by 275 persons

a bullet is dropped from the same height when another bullet is fired horizontally.they will hit the ground?

A stone is dropped from a certain height

Asked by admin @ in Physics viewed by 264 persons

A stone is dropped from a certain height after falling for 5sec. the stone breaks through pane of glass andinstantly loses half of its velocity. If the stonethen …

A stone is dropped from a height of 20m

Asked by admin @ in Physics viewed by 275 persons

A stone is dropped from a height of 20m. (i) How long will it take to reach the ground?(ii) what will be its speed when it hits the ground?

A ball is dropped from a high rise platform

Asked by admin @ in Physics viewed by 359 persons

A ball is dropped from a high rise platform at t=0 starting from rest. After 6 seconds another ball is thrown downwards from the same platform with a speed v. …

A 2kg block is dropped from a height of 0.45

Asked by admin @ in Physics viewed by 276 persons

A 2kg block is dropped from a height of 0.4 m into into a spring of force constant K = 1960 N/m the maximum distance the spring will be compressed …

A ball is dropped from the top of a building

Asked by admin @ in Mathematics viewed by 338 persons

A ball dropped from the top of the building can be modeled by the function f(t)=-16t^2 + 36 , where t represents time in seconds after the ball was dropped. …

A body is dropped from a height h

Asked by admin @ in Physics viewed by 347 persons

A body is dropped from height H. What is the time taken to cover second half of the journey? 1. 2√(2H/g) 2. √(H/g) 3. √(H/g)*(√2-1) 4. √(2H/g)*(1/(√2-1))

A stone is dropped from a height h

Asked by admin @ in Physics viewed by 567 persons

A stone is dropped from a height h. It hits the ground with a certain momentum P. If the same stone is dropped from a height 100% more than the …

Most viewed questions in Physics


Jeevandeep health and physical education std 10 answers pdf

Asked by admin @ in Physics viewed by 11067 persons


Hc verma physics class 9 solutions of describing motion

Asked by admin @ in Physics viewed by 2664 persons


How to leave nightmare land answer key

Asked by maham237 @ in Physics viewed by 1594 persons



Base area and stability of some objects with different shapes

Asked by admin @ in Physics viewed by 1525 persons


Which of the following statements about safe lifting are correct

Asked by admin @ in Physics viewed by 1512 persons


Porous water-absorbing mass of fibers

Asked by wiki @ in Physics viewed by 1494 persons



Absorption of water by filter paper is due to

Asked by admin @ in Physics viewed by 1432 persons


A composite wire of uniform diameter 3mm

Asked by admin @ in Physics viewed by 1403 persons


At a distance l 400m from the traffic light

Asked by admin @ in Physics viewed by 1320 persons



A rocket of mass m is launched straight up with thrust f⃗ thrust.

Asked by maham237 @ in Physics viewed by 1311 persons


Mind map for light reflection and refraction class 10

Asked by admin @ in Physics viewed by 1143 persons



A thief runs at a speed of 10m s

Asked by admin @ in Physics viewed by 1095 persons


A 5.8 x 10 4 watt elevator motor can lift

Asked by maham237 @ in Physics viewed by 1080 persons