Calculate the New Velocity and the Velocity of a Pendulum Mass

[Justinboln]

Homework Statement

How much work is required to move the pendulum to its new
position?

Calculate the new velocity of the sled and slide.

If the pendulum swings from this position, what will be the
velocity of the mass at the instant it passes through the lowest
position of its path?

Relevant Equations

no sure which formula to use

Question 1:

A pendulum 2.2m long has a mass of 8.5kg suspended from it. The
pendulum is initially in a vertical position and is moved to new
position 35 degrees from the vertical.

(a) How much work is required to move the pendulum to its new
position?

(b) If the pendulum swings from this position, what will be the
velocity of the mass at the instant it passes through the lowest
position of its path?Question 2:

A snow sled of mass 12kg is moving on a level snow cover (assumed
frictionless) at 1.2m/s. A child of mass 36kg running at 1.8m/s in the
same direction jumps onto the sled.

(a) Calculate the new velocity of the sled and slide.

Not sure Which formulas to use for each question. can you elaborate on how to solve them? Thank you.

 

[Delta2]

Q2 is straightforward application of conservation of momentum.
Q1 both a) and b) are about application of the principle of conservation of energy.

I am sorry i am not allowed to say more according to the rules of PF you got to show us your best attempt at solution, which means you have to work abit yourself!