Physics word problem please help!!?

Question

The bird perched on the swing shown below has a mass of 40.9 g, and the base of the swing, y = 7.87 cm below the hook, has a mass of 155 g. The swing and bird are originally at rest, and then the bird takes off horizontally at 2.02 m/s. How high will the base of the swing rise above its original level? Disregard friction.

Answer 1

♠ the bird perched on the swing, so their common momentum M=0;
♣ after the bird took off, their common momentum M=M1+M2, where M1=m1*v1, m1=40.9g, v1=2.02m/s,
M2=m2*v2, m2=155g, v2 is velocity of the swing;
♦ and momentum conserves; M=M; M1+M2=0;
m1*v1 + m2*v2 = 0, hence v2= m1*v1/m2;
♥ this corresponds to kinetic energy of the swing
E=0.5*m2*v2^2, that transforms into potential energy E=m2*g*h;
E=E; or; m2*g*h =0.5*m2*v2^2,
hence “how-high” h=0.5*v2^2/g = (0.5/g)*(m1*v1/m2)^2 =
= (0.5/9.8)*(40.9*2.02/155)^2 =0.0145m = 1.45cm;

Answer 2

Using conservation of momentum, compute the translational speed of the swing
040.9*2.02-155*v=0
v=0.53 m/s

Now, using energy, compute the height
.5*0.155*0.53^2=0.155*9.81*h
solve for h
h=0.14 m

j

Answer 3

If we anticipate the motorcycles are traveling in the direction of one yet another, they're going to fulfill in one hour. with the aid of fact the bee flies at 30 km/hr, it is going to holiday 30 km interior the single hour it takes the motorcycles to fulfill.