A pendulum bob (mb = 1.0 kg) is held horizontally above the ground. The length o

Question

A pendulum bob (mb = 1.0 kg) is held horizontally above the ground. The length of the string is 0.30 m. It is then released, and it swings down and collides with the cart (mc = 2.0 kg). The cart is initially at rest. After colliding with the cart, the pendulum bob stops and the cart starts moving. Ignore friction and air resistance. A) What is the velocity of the pendulum bob just before it hits the cart? B) What is the velocity of the cart just after being hit by the pendulum bob.

I noticed that this problem is a two-part problem so then I used momentum as MbVi = McVcf for part 1. Then for part 2 I got used energies such as potential = kinetic (Ug=Ke )

so i get (9.8)(.30)=1/2(2)Vc^2 =1.71 and then I get the same for the A. v=1.71

Explanation / Answer

Apply conservation of energy

mgh = 1/2 mv^2

mgL( 1- cos 90) = 1/2 mv^2

v= sqrt 2gL

= sqrt 2 ( 9.8) ( 0.3)

=2.424 m/s

since the collision is elastic the final velcoity of cart is

v2= 2m1/ m1+ m2 * u1

= 2( 1)/ 1+ 2 * 2.424 m/s

=1.616 m/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.