At the left. 6.
1. Work equals
A force x distance
B. force - distance
C. force + distance.
The force you apply to a machine
is the
A. input force.
B. output force.
C. efficiency.
2.
The unit of work is the
A. watt.
B. newton.
C. joule.
7.
The efficiency of all real
machines is
A. greater than 100%
B. equal to 100%
C. less than 100%
3.
Power is the amount of
A. work done per unit of time.
B. force on a certain area.
C. pressure in a volume of liquid.
8.
4.
The unit for power is the
A. joule.
B. Meter per second
C. watt.
The fixed point that a lever rotates
around is called the
A. fulcrum.
B. input force.
C. wedge.
9.
5.
A machine cannot change the
A. direction of the input force.
B. amount of work needed to do
A screwdriver is an example of a
simple machine called a
A. pulley.
B. screw
C. wheel and axle.
a task.
C. distance over which a force
is applied
10.
Your front teeth are
A. wedges.
B. levers.
C. compound machines.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

did anyone actually do this? like if anyone has submitted this i rly need .