It depends on the type of question, mechanical condition and given values,
You can use the formula,
Coefficient of kinetic friction = Force of Kinetic friction / Normal force (perpendicular to contacting surfaces)
Hope this helps!
Answer:
a) 11.2 g
b) 3.73 g.
Explanation:
a) If we assume temperature of mixture to be 100°C , heat released by steam will be 11.2 x 540 = 6048 cals and heat gain gained by will be
79 x 80 + 79 x 1 x 100 = 14220 cals . Since former heat is less than later heat ,water will not be warmed up to 100°C. Let equilibrium temperature be t .
Heat gained by water = 79 x 80 + 79 x 1 x t = 11.2 x 540 + 11.2( 100 - t )
t = 9.4°
amount of steam condensed = 11.2 g.
b) In this case, whole of water will be warmed up to 100°C as steam is much .heat required by water to warm up to boiling point
= 11.2 x 80 + 11.2 x 100 = 2016 cals
amount of steam condensed = 2016 / 540 = 3.73 g .
Answer:
initial magnitude will be 9 N and direction will be to the right
Explanation:
force= 9N
mass m= 330 grams
acceleartion = a
from newtons 2nd law of motion we write

dP is the chage in momentum dt is time taken and F is the Force applied

this shows that the rate of change of momentum is 9 N
we also know that F= ma
putting values we get

a= 27.27 m/sec^2
The direction of acceleration will along the direction of force applied. So will be the direction of change momentum as in F=ma, mass is the scalar quantity and direction of force dictates the direction of motion. Hence, initial magnitude will be 9N and direction will be to the right
Answer:
Part A
it would take 6 sec
it would take 3 sec
Explanation:
We are told that the power supplied to the wheel is constant which means that the sport car is gaining energy i.e
Hence if power is constantly supplied energy constantly increase
From the formula of the Kinetic energy

we can see that as the speed doubles from 29 mph to 58 mph the energy needed is
= 4 times of the energy from the formula
Also the time needed would also be 4 times because energy i directly proportional to time
Hence to reach 58mph the time that it would take is
=
We are told that the ground pushes the car with a constant force and
F = ma
this means that the acceleration is also constant
now from newtons law
v = u +at
Looking at it we see that final velocity is directly proportional with time
hence it would take twice the time to reach twice the final velocity
Time to reach 58mph = 3 s
since time to reach 29 mph(
) =(
)1.5 s