arrrghhhhh!!! help plz!!

[Ice-cream]

I've got some physics questions which I think are meant to be VERY basic and easy but i can't do them or get the right answer! can some1 plz help me out with some tips, suggestions or the steps i should take in trying to solve these questions?

 

1. A gymnast is swinging on a high bar. At the top of his swing his speed is momentarily zero and his centre of mass is 1.1m above the bar. At the bottom of his swing his centre of mass is now the same distance below the bar. What will be his speed at the bottom of the swing? (Ans: 6.6m/s)

 

2. What power must a crane generate to life 1 tonne of bricks at the speed of 1m/s? (10^4 W)

 

3. The human nervous system can propagate nerve impusles at about 10^2 m/s. Estimate the time taken for a nerve impusle that is generated when your finger touches a hot object to travel the length of your arm. (8ms)

[swansont]

I've got some physics questions which I think are meant to be VERY basic and easy but i can't do them or get the right answer! can some1 plz help me out with some tips' date=' suggestions or the steps i should take in trying to solve these questions?

 

1. A gymnast is swinging on a high bar. At the top of his swing his speed is momentarily zero and his centre of mass is 1.1m above the bar. At the bottom of his swing his centre of mass is now the same distance below the bar. What will be his speed at the bottom of the swing? (Ans: 6.6m/s)

 

2. What power must a crane generate to life 1 tonne of bricks at the speed of 1m/s? (10^4 W)

 

3. The human nervous system can propagate nerve impusles at about 10^2 m/s. Estimate the time taken for a nerve impusle that is generated when your finger touches a hot object to travel the length of your arm. (8ms)[/quote']

 

1. PE is converted to KE.

 

2. If F and v are constant, P=F(dot)v

 

3. v=d/t solve for t

[Ice-cream]

i got da answers!!!! thank you soooooooooooo much!!!