Grade 12th passMechanics

a body is projected vertically upward from top of a tower with a velocity of 40 m per second .Tower being 180 m and after t second another body B allowed to fall from same point. Both bodies reach the ground simultaneously .calculate t and velocities of A and B on reaching the grounda

Sachin mishra

7 Years agoGrade 12th pass

1 Answer

Devang

7 Years ago

let assume that object A throw vertically upward with velocity of V₀ = 40 m/s on the roof of the tower.

hight of tower H = 180m

Maximum hight attained by object = V₀² / 2g

= 40 * 40 / 2 * 10 (asume g= 10m/s² )

h_max = 80m

time taken by the object to reach maximum hight is = V₀ / g

= 40 / 10

T₁ = 4 sec.

time taken by object to reach the ground from maximum hight = (2 * h / g) ^½ (where h = H + h_max

= 180+80 = 260)

= (2 * 260 / 10)^½ . T₂ = 7.21 sec

total time to reach the ground is T_A = T₁ + T₂

= 7.21 + 4

T_A = 11.21 sec …...... (1)

velocity when object reach the ground = ( 2 *g *h)^½

= (2 *10 *260)^½

V_A = 72.11 m/s

let assume that onather object B is fall from top of the tower.

time taken by object B to reach the ground = (2 * H / g) ^½

= (2 * 180 / 10)^½

T_B = 6 sec ….......(2)

velocity of object B when it touches the ground V_B = ( 2 *g *H)^½

= (2 *10 *180)^½

V_B= 60 m

thrown upward object A and , after time t sec object B fall down

and both object reaches the ground at same time

then t = T_A – T_B from (1) & (2)

= 11.21 – 6

t = 5.21 sec

Three identical balls are placed on a frictionless horizontal surface touching each other. They stick to each other because of adhesive. Another ball of same radius and mass m is placed over the void created by the three balls. Find the forces applied by the balls kept on the floor to each other if the system remains in equilibrium.

mechanics

1 Answer Available

Last Activity: 9 Months ago

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

11
21
31
41

mechanics

1 Answer Available

Last Activity: 9 Months ago

A metal strip clamped at one end vibrates with a frequency of 20 Hz and amplitude of 5 mm
at the free end, where a small mass of 2 g is positioned. determine
(i) The velocity of the end when passing through the zero position
(ii) The acceleration at maximum displacement
(iii) The maximum kinetic energy of the mass

mechanics

2 Answers Available

Last Activity: 3 Years ago

An object of mass m = 0.25 kg oscillates in a fluid at the end of a vertical spring of spring
constant kH = 85 N/m, see Fig.1. The effect of the fluid resistance is governed by the
damping constant b = 0.07kg/s.
(i) Find the period of the damped oscillation.
(ii) By what percentage does the amplitude of the oscillation decrease in each cycle?

mechanics

1 Answer Available

Last Activity: 3 Years ago

If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0

mechanics

1 Answer Available

Last Activity: 3 Years ago

View all Questions

a body is projected vertically upward from top of a tower with a velocity of 40 m per second .Tower being 180 m and after t second another body B allowed to fall from same point. Both bodies reach the ground simultaneously .calculate t and velocities of A and B on reaching the grounda

Sachin mishra

1 Answer

Devang

Other Related Questions on mechanics

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.11213141

If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

11
21
31
41