It's Z.
Without any force acting on it an object travels in a straight line.
In order to bend away from a straight line the object needs a force acting on it.
In order to move along a circle, the force on the object points toward the center of the circle. It's called the centripetal force.
Since the object's direction is changing it has acceleration.
The acceleration points toward the center of the circle.
Given:
v(final velocity)= 7.5 m/s
t(time taken to pedal along)=4.5 s
Displacement (s)=19 m
Now we know that
s=ut+1/2(at^2)
Where s is the displacement measured in m
u is the initial velocity measured in m/sec
a is the acceleration measured in m/s^2.
t is the time taken to cover this distance.
Substituting the given values in the above formula we get
19= 4.5u+1/2(a x 4.5 x 4.5)
20.25 a + 9 u = 38
Now we also know that
v= u + at
Substituting the given values in the above formula we get
7.5= u + 4.5a
Solving for u and a from the above equations we get
u = 0.944m/s
a= 1.45 m/s^2
Thus the initial velocity is 0.944 m/s
Answer:
I believe the answer is D on E2020. Hope this helps
The answer to your question is B. When light hits something relatively flat, smooth and shiny, it is reflected by the surface, allowing nearby objects to be seen on the surface.
The ultimate fate of a star depends on its mass.
A massive star ends with a violent explosion called a supernova.
The matter ejected in a supernova explosion becomes a glowing supernova remnant.
Toward the end of its life, a massive supergiant star
has a central iron core, surrounded by a shell where
silicon is being fused to iron, surrounded by a shell
where oxygen is being fused, surrounded by a shell where
carbon is being fused, surrounded by a shell where helium is
being fused, surrounded by a shell where hydrogen is
being fused.
