Answer:
v=32.49 m/s
Explanation:
Given that
Distance ,d= 66 m
Initial speed of the car ,u = 0 m/s
Coefficient of friction ,μ = 0.8
Lets take the total mass of the car = m
The acceleration of the car is given as
a = μ g ( g= 10 m/s² )
Now by putting the values in the above equation we get
a= 0.8 x 10 m/s²
a= 8 m/s²
We know that ,final speed is given as
v²= u ²+ 2 a d
Now putting the value
v²=0² + 2 x 8 x 66
v²= 1056
v=32.49 m/s
Answer:

Explanation:
It is given that,
Mass of the grindstone, m = 3 kg
Radius of the grindstone, r = 8 cm = 0.08 m
Initial speed of the grindstone, 
Finally it shuts off, 
Time taken, t = 10 s
Let
is the angular acceleration of the grindstone. Using the formula of rotational kinematics as :



Let
is the number of revolutions of the grindstone after the power is shut off. Now using the third equation of rotational kinematics as :





or

So, the number of revolutions of the grindstone after the power is shut off is 50.
Answer:
can exchange energy with its surroundings through heat and work transfer. In other words, work and heat are the forms that energy can be transferred across the system boundary.
Ok I know this from other stuff potassium nitrate would completely dissolve in a 100 g on was at 30 c would be 60 but this is 40 so I’m not really sure and I don’t what to ok give you a bad grade but if I had to guess I would go with 65 grams