physics homework help needed!?

Question

001 An air puck of mass 0.166 kg is tied to a string
and allowed to revolve in a circle of radius
1.17 m on a horizontal, frictionless table. The
other end of the string passes through a hole
in the center of the table and a mass of 0.54 kg
is tied to it. The suspended mass remains in
equilibrium while the puck revolves.
The acceleration of gravity is 9.8 m/s^2
What is the tension in the string?
in units of N.
002 What is the horizontal force acting on the
puck? in units of N.
003 What is the speed of the puck?units of m/s.
004 A 6.95 kg bowling ball moves at 4.6 m/s.
How fast must a(n) 29.8 g golf ball move
so that the two balls have the same kinetic
energy? in units of m/s.
005 A racing car has a mass of 1660 kg.
The acceleration of gravity is 9.8 m/s^2 .
What is its kinetic energy if it has a speed
of 132 km/h? in units of J
006 Lee pushes horizontally with a force of 59 N
on a 38 kg mass for 14 m acros a floor.
Calculate the amount of work Lee did. in Joul

Answer 1

1. Assuming no friction the tension in the string is equal to the weight of the suspended mass

.54*9.8
5.3 N

2. The horizontal force is the tension 5.3 N

3. The speed will be related to
F=m* w^2* R

or
F=m*v^2/R

5.3=.166*v^2/1.17
v=sqrt(5.3*1.17/.166)

6.11 m/s

4. .5*6.95*4.6^2=.5*.0298*v^2

v=4.6*sqrt(6.95/.0298)

=70.25

5. .5*1660*(132*60*60/1000)^2

=187 Mega J

6. 59*14

826 J

j

Answer 2

the pump has to provide pressure to support a column of water up to the 13th floor in addition to the desired pressure 2) go back and review the section on pascal's and archimedes' principles