Answer:
Art
Explanation:
Polly's line is linear, while arts line is going up with constant velocity. There for art is going faster.
Answer:
Force of friction, f = 751.97 N
Explanation:
it is given that,
Mass of the car, m = 1100 kg
It is parked on a 4° incline. We need to find the force of friction keeping the car from sliding down the incline.
From the attached figure, it is clear that the normal and its weight is acting on the car. f is the force of friction such that it balances the x component of its weight i.e.


f = 751.97 N
So, the force of friction on the car is 751.97 N. Hence, this is the required solution.
(a) 6.04 rev/s
The speed of the ball is given by:

where
is the angular speed
r is the distance of the ball from the centre of the circle
In situation 1), we have

r = 0.600 m
So the speed of the ball is

In situation 2), we have

r = 0.900 m
So the speed of the ball is

So, the ball has greater speed when rotating at 6.04 rev/s.
(b) 
The centripetal acceleration of the ball is given by

where
v is the speed
r is the distance of the ball from the centre of the trajectory
For situation 1),
v = 30.6 m/s
r = 0.600 m
So the centripetal acceleration is

(c) 
For situation 2 we have
v = 34.1 m/s
r = 0.900 m
So the centripetal acceleration is

An object that moves in a uniform circular motion would have a constant speed. However, we would not say that acceleration would be zero. The object would be accelerating due to the changes in the direction. Acceleration or this case would be the ratio of the square of its velocity an the radius of the circular motion. We would calculate as follows:
Acceleration = velocity^2 / radius
velocity = 2035 rpm (1 min / 60 s) (5.862 cm)
velocity = 198.8195 cm/s
Acceleration = (198.8195 cm/s)^2 / 5.862 cm = 33.92 cm/s^2
Therefore, the acceleration of the edge of the rotor would be 33.92 cm per s^2.