A bulldozer pushes on a boulder with a force of 600 N. It accelerates at 3 m/s. Find mass.

A 60kg bicyclist (including the bicycle) is pedaling to the

Fittoniya [83]

a) 4 forces

b) 186 N

c) 246 N

Explanation:

a)

Let's count the forces acting on the bicylist:

1) Weight ( $W=mg$ ): this is the gravitational force exerted on the bicyclist by the Earth, which pulls the bicyclist towards the Earth's centre; so, this force acts downward (m = mass of the bicyclist, g = acceleration due to gravity)

2) Normal reaction (N): this is the reaction force exerted by the road on the bicyclist. This force acts vertically upward, and it balances the weight, so its magnitude is equal to the weight of the bicyclist, and its direction is opposite

3) Applied force ( $F_A$ ): this is the force exerted by the bicylicist to push the bike forward. Its direction is forward

4) Air drag ( $R$ ): this is the force exerted by the air on the bicyclist and resisting the motion of the bike; its direction is opposite to the motion of the bike, so it is in the backward direction

So, we have 4 forces in total.

b)

Here we can find the net force on the bicyclist by using Newton's second law of motion, which states that the net force acting on a body is equal to the product between the mass of the body and its acceleration:

$F_{net}=ma$

where

$F_{net}$ is the net force

m is the mass of the body

a is its acceleration

In this problem we have:

m = 60 kg is the mass of the bicyclist

$a=3.1 m/s^2$ is its acceleration

Substituting, we find the net force on the bicyclist:

$F_{net}=(60)(3.1)=186 N$

c)

We can write the net force acting on the bicyclist in the horizontal direction as the resultant of the two forces acting along this direction, so:

$F_{net}=F_a-R$

where:

$F_{net}$ is the net force

$F_a$ is the applied force (forward)

$R$ is the air drag (backward)

In this problem we have:

$F_{net}=186 N$ is the net force (found in part b)

$R=60 N$ is the magnitude of the air drag

Solving for $F_a$ , we find the force produced by the bicyclist while pedaling:

$F_a=F_{net}+R=186+60=246 N$

3 0

3 years ago

Breathing on a cold window can cause it to fog up. which change of state causes this

Dominik [7]

When you breathe on a cold window and it fogs up, that change of state is called: Condensation.

Condensation is: The process in which molecules of a gas slow down, come together, and form a liquid water that collects as droplets on a cold surface when humid air is in contact with it.

I know this because I learned it in science class in school.

Hope I helped!

- Debbie

3 0

4 years ago

How long does it take a car traveling at 50 mph to travel 75 miles? Use one of the following to find the answer.

yanalaym [24]

Answer:

90 Minutes

Explanation:

t = d / v

t = 75 / 50

t = 1.5 hour

t = 90 minutes.

8 0

3 years ago

A white-blue star is hotter than a red star.

Katena32 [7]

This is true!!

Good luck hope this helped!

4 0

4 years ago

Read 2 more answers

Which of the following provides evidence that geologic activity occurred in the past on Earth's Moon?

Bingel [31]

Answer: d) the presence of solidified lava flows on the Moon

Explanation:

A geological activity means an occurrence of event such as volcanic eruption, earthquake, sedimentation, erosion etc. The revolution of the Moon around the Earth , the axial tilt of the Moon or the phases of the Moon are not surface features. hence, these events cannot provide the evidence of geological activity in the past of Moon.

The surface features of moon such as Mares, Craters, mountains, Rays and rills are the proof of some geological activity on the Moon. Mares are the dark patches on the moon's surface formed of solidified lava. Due to negligible atmosphere on the moon, the meteors strike its surface and cause craters to form. Thus, the correct answer is d.

6 0

3 years ago

A bulldozer pushes on a boulder with a force of 600 N. It accelerates at 3 m/s. Find mass.​

A bulldozer pushes on a boulder with a force of 600 N. It accelerates at 3 m/s. Find mass.