Answer: because she is pedalling at her maximum speed produced by the maximum force applied. At constant speed, acceleration is equal to zero.
Explanation:
Pedalling of bicycle involves application of force. The force applied produces circular motion to the tires which eventually transform into linear speed.
V = wr
Where V = linear speed
W = angular speed
r = radius.
Change in speed V will lead to acceleration or deceleration depending on increase or decrease in speed.
If she stops accelerating, then, she must have applied force that makes her pedalling at maximum speed. She is also maintaining this uniform (constant ) speed. After reaching her maximum speed.
At constant speed, acceleration = 0
Base on this explanation, even though she is still pedalling as fast as she can, which at constant speed, she will stop accelerating and her speed reaches a maximum value because she is pedalling at her applied maximum force.
Answer:
Both these motions are caused by the Gravitational force of earth.
Explanation:
Both these motions are caused by the Gravitational force of earth.
The moon would be bright and the earth would be darker because the sun is on the opposite side of the earth at that time and the light from it is reflecting off the moon to produce light upon the nigh also.......
You wouldn’t see the sun a night...
Unless you lived in the north/south pole
Answer:
.
Explanation:
When the ball is placed in this pool of water, part of the ball would be beneath the surface of the pool. The volume of the water that this ball displaced is equal to the volume of the ball that is beneath the water surface.
The buoyancy force on this ball would be equal in magnitude to the weight of water that this ball has displaced.
Let 
denote the mass of this ball. Let 
denote the mass of water that this ball has displaced.
Let 
denote the gravitational field strength. The weight of this ball would be 
. Likewise, the weight of water displaced would be 
.
For this ball to stay afloat, the buoyancy force on this ball should be greater than or equal to the weight of this ball. In other words:
.
At the same time, buoyancy is equal in magnitude the the weight of water displaced. Thus:
.
Therefore:
.
.
In other words, the mass of water that this ball displaced should be greater than or equal to the mass of of the ball. Let 
denote the density of water. The volume of water that this ball should displace would be:
.
Given that 
while 
:
.
In other words, for this ball to stay afloat, at least of the volume of this ball should be under water. Therefore, the volume of this ball should be at least 
.
Answer:
(a) The equivalent spring constant is 598.485 N/m
(b) The work done is 46.926 J
Explanation:
From Hooke's law of elasticity
K (spring constant) = F/e
F is the range of force exerted = 237 - 0 = 237 N
e is the extension of bowstring = 0.396 m
K = F/e = 237/0.396 = 598.485 N/m
Work done = 1/2 Fe = 1/2 × 237 × 0.396 = 46.926 J
