How many atoms are in something determines its?

A child of mass 40.0 kg is in a roller coaster car that travels in a loop of radius 7.00 m. at point a the speed of the car is 1

pav-90 [236]

I attached the missing picture.
The force of seat acting on the child is a reaction the force of child pressing down on the seat. This is the third Newton's law. The force of a child pressing down the seat and the force of the seat pushing up on the child are the same.
There two forces acting on the child. The first one is the gravitational force and the second one is centrifugal force. In this example, the force of gravity is always pulling down, but centrifugal force always acts away from the center of circular motion.
Part A
For point A we have:
$F_a=F_cf-F_g$
In this case, the forces are aligned, centrifugal is pointing up and gravitational is pulling down.
$F_a=m\frac{v^2}{r}-mg=179 $N$
Part B
At the point, B situation is a bit more complicated. In this case force of gravity and centrifugal force are not aligned. We have to look at y components of this forces, y-axis, in this case, is just pointing upward.
$F=F_{cf}\cos(30)-mg=m\frac{v^2}{r}\cos(30)-mg=153.2$N$
Part C
The child will stay in place at point A when centrifugal force and force of gravity are in balance:
$F_g=F_{cf}\\
mg=m\frac{v^2}{r}\\
gr=v^2\\
v=\sqrt{gr}=8.29\frac{m}{s}$

6 0

3 years ago

Select the correct answer. Which chemical reaction absorbs energy? A. photosynthesis B. explosion C. current produced by a batte

zavuch27 [327]

Answer:

Explanation:

Photosynthesis

4 0

3 years ago

Read 2 more answers

What is the answer to this question

scoundrel [369]

Answer: A

Explanation:

Molecules speed up as heat is added

For example when water is heated as the water gets hotter the molecules speed up causing the water to boil and change phases into a gas (this is called evaporation)

In an ice cube the water molecules are frozen (barely moving compressed tight together) as the ice cube heats up the molecules start speeding up and moving further apart as the ice cube turns into liquid form. So as heat is added molecules speed up, move faster and spread further apart

7 0

3 years ago

Will mark brainliest.

egoroff_w [7]

Answer:

pls can you get a clearer image, then u can report back to me

6 0

3 years ago

If he were able to maintain this constant rate of acceleration, what would have been his speed as he finished the race?

Law Incorporation [45]

a) 4.8 m/s² his average acceleration during the first 2.5 s

b) 15 m distance he cover during the first 2.5 seconds.

c) 31 m/s his speed as he finished the race.

<h3>(a) How to calculate the Average Acceleration ?</h3>

Average acceleration is calculated by using Newtons first law of motion

v = u + at

where

u is initial velocity

v is final velocity

a is constant acceleration

t is time

Given u = 0m/s , v = 12 m/s and t = 2.5 sec

Therefore average acceleration is given by

$a=\frac{v}{t}$

$a=\frac{12}{2.5}$

a = 4.8 m/sec²

b) Here we will use newtons second law of motion

$s=ut+\frac{1}{2}at^{2}$

On substituting value we get

s = 15m

c) Here we will use newtons third law of motion

v² = u² + 2as

Here u = 0 , a = 4.8 m/s² and s = 100 m

Therefore

v² = 960

v = 31 m/s

Disclaimer: the question was given incomplete in the portal. Here is the complete question.

Question: Usain Bolt's 100m sprint Runner set the world record for the100 meter sprint during the 2009World Championships in Berlin with a time of 9.58 s, reaching a top speed of 12 m/s in about 2.5 s.

a. What was his average acceleration during the first 2.5 s?

b. What distance did he cover during the first 2.5 seconds, assuming his acceleration was constant?

c. If he were able to maintain this constant rate of acceleration, what would have been his speed as he finished the race?

Learn more about Newtons law of motion here:

brainly.com/question/12525794

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5 0

2 years ago