help@askiitians.com

+91-87964 74404

Grade 11Mechanics

A ball thrown at different angles with the same speed u and from the same point and it has the same range in both cases. If y1 and y2 are the heights attained in two cases, then y1 + y2 is equal to

u^2/g

2u^2/g

u^2/2g

u^2/4g

Prathamesh Jagtap

9 Years agoGrade 11

1 Answer

Raman Mishra

9 Years ago

Two projectiles have the same range if they are launched at angles which are complementary to each other. That is, if the 1^st projectile is launched at an angle $\theta$ from the horizontal, then the other projectile must be launched at an angle of $\frac{\pi }{2} -\theta$ from the horizontal for having the same range.

Now, maximum height of a projectile = $h = \frac{u^{2}\sin ^{2}\theta}{2g}$

For the 1^st ball we have $h_{1} = \frac{u^{2}\sin ^{2}\theta}{2g}$

For the 2^nd ball, we have $h_{2} = \frac{u^{2}\sin ^{2}(\frac{\pi }{2}-\theta )}{2g}$ $= \frac{u^{2}\cos ^{2}\theta }{2g}$

$\therefore$ h₁ + h₂ = u²/2g

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: 10 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: 10 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