A :-) for this question , we should apply
F = GMm by d^2
( For making the calculation easy , first remove the decimals )
Given : G = 6.7 x 10^-11 Nm^2 / kg^2
= 67 x 10^-12 Nm^2 / Kg^2
M = 65 kg
m = 40 kg
d = 0.5 m
Solution -
F = GMm by d^2
F = 67 x 10^-12 x 65 x 40 by 0.5 x 0.5
F = 4355 x 40 x 10^-12 by 0.25
F = 174200 x 10^-12 by 0.25
F = 696800 x 10^-12
.:. The Gravitational force between mark and Katie is 696800 x 10^-12
a) See free-body diagram in attachment
b) The acceleration is 
Explanation:
a)
The free-body diagram of an object is a diagram representing all the forces acting on the object. Each force is represented by a vector of length proportional to the magnitude of the force, pointing in the same direction as the force.
The free-body diagram for this object is shown in the figure in attachment.
There are three forces acting on the object:
- The weight of the object, labelled as
(where m is the mass of the object and g is the acceleration of gravity), acting downward - The applied force,
, acting up along the plane - The force of friction,
, acting down along the plane
b)
In order to find the acceleration of the object, we need to write the equation of the forces acting along the direction parallel to the incline. We have:

where:
is the applied force, pushing forward
is the frictional force, acting backward
is the component of the weight parallel to the incline, acting backward, where
m = 2 kg is the mass of the object
is the acceleration of gravity
is the angle between the horizontal and the incline (it is not given in the problem, so I assumed this value)
a is the acceleration
Solving for a, we find:

Learn more about inclined planes:
brainly.com/question/5884009
#LearnwithBrainly
Answer:
Part a)
P = 1200 Watt
Part b)
P = 480 W
Part c)

Explanation:
Part a)
Power consumed by blow dryer is given as

here supply voltage is given as

current rating of blow dryer is given as



Part b)
Power consumed by vacuum cleaner is given as

here supply voltage is given as

current rating of vacuum cleaner is given as



Part c)
Energy consumed in a given interval of time is given as

now we have to find the ratio of energy consumed in time interval of 11 minutes
so we have

now we have


There are some missing data in the text of the problem. I've found them online:
a) coefficient of friction dry steel piston - steel cilinder: 0.3
b) coefficient of friction with oil in between the surfaces: 0.03
Solution:
a) The force F applied by the person (300 N) must be at least equal to the frictional force, given by:

where

is the coefficient of friction, while N is the normal force. So we have:

since we know that F=300 N and

, we can find N, the magnitude of the normal force:

b) The problem is identical to that of the first part; however, this time the coefficienct of friction is

due to the presence of the oil. Therefore, we have: