1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kotykmax [81]
3 years ago
12

A pencil rolls horizontally of a 1 meter high desk and lands .25 meters from the base of the desk. How fast was the pencil rolli

ng when it left the desk?
Physics
1 answer:
vovikov84 [41]3 years ago
4 0

Answer: 0.55 m/s

Explanation:

This situation is related to projectile motion (also called parabolic motion), where the main equations are as follows:

x=V_{o} cos\theta t (1)

y=y_{o}+Vo sin \theta t + \frac{g}{2}t^{2} (2)

Where:

x=0.25 m is the horizontal displacement of the pencil

V_{o} is the pencil's initial velocity

\theta=0\° since we are told the pencil rolls <u>horizontally</u> before falling

t is the time since the pencil falls until it hits the ground

y_{o}=1 m  is the initial height of the pencil

y=0  is the final height of the pencil (when it finally hits the ground)

g=-9.8m/s^{2}  is the acceleration due gravity, always acting vertically downwards

Begining with (1):

x=V_{o} cos(0\°) t (3)

x=V_{o}t (4)

Finding t from (2):

0=1 m+ \frac{-9.8m/s^{2}}{2}t^{2} (5)

t=\sqrt{\frac{-2y_{o}}{g}} (6)

Substituting (6) in (4):

x=V_{o}\sqrt{\frac{-2y_{o}}{g}} (7)

Isolating V_{o}:

V_{o}=\frac{x}{\sqrt{\frac{-2y_{o}}{g}}} (8)

V_{o}=\frac{0.25 m}{\sqrt{\frac{-2(1 m)}{-9.8m/s^{2}}}} (9)

Finally:

V_{o}=0.55 m/s

You might be interested in
How much work is done to increase the speed of a 1.0 kg toy car by 5.0 m/s?
soldi70 [24.7K]

Answer:

The correct option is (b).

Explanation:

We need to find the work done to increase the speed of a 1 kg toy car by 5 m/s.

We know that, the work done is equal to the kinetic energy of an object i.e.

W=\Delta K\\\\W=\dfrac{1}{2}mv^2\\\\W=\dfrac{1}{2}\times 1\times 5^2\\W=12.5\ J

So, 12.5 J of work is done to increase the speed of a 1.0 kg toy car by 5.0 m/s.

6 0
3 years ago
A meter stick is suspended vertically at a pivot point 22 cm from the top end. It is rotated on the pivot until it is horizontal
suter [353]

Answer:

5.82812 rad/s

Explanation:

L = Length of meter stick = 1 m = 100 cm

m_c = The center of mass of the stick = \frac{L}{2}-0.22=0.5-0.22=0.28\ m

\omega = Angular velocity

Moment of inertia of the system is given by

I=I_c+mr^2\\\Rightarrow I=\frac{mL^2}{12}+mr^2\\\Rightarrow I=\frac{m1^2}{12}+m0.28^2\\\Rightarrow I=m(\frac{1}{12}+0.0784)

As the energy in the system is conserved

mgh=I\frac{\omega^2}{2}\\\Rightarrow mgh=m(\frac{1}{12}+0.0784)\frac{\omega^2}{2}\\\Rightarrow gh=(\frac{1}{12}+0.0784)\frac{\omega^2}{2}\\\Rightarrow \omega=\sqrt{\frac{2gh}{\frac{1}{12}+0.0784}}\\\Rightarrow \omega=\sqrt{\frac{2\times 9.81\times 0.28}{\frac{1}{12}+0.0784}}\\\Rightarrow \omega=5.82812\ rad/s

The maximum angular velocity is 5.82812 rad/s

4 0
3 years ago
Which of the following statements about blood alcohol concentration (BAC) are true?
mars1129 [50]
D) Neither A or B are correct
5 0
3 years ago
Read 2 more answers
You kick a soccer ball across a field the ball travels across the field and slowly comes to a stop. Since the ball slowly comes
marysya [2.9K]

Answer:

It slowly decreases and the friction acting on it slowing it down becomes the bigger net force, if that makes sense :)

Explanation:

6 0
2 years ago
In which object more force has to be applied to move in between two objects of mas 11
jeka94

Answer:

my butt

Explanation:

2x2 by the power of 10 divide that 98

4 0
3 years ago
Other questions:
  • What is the kinetic energy of an object that has a mass of 50.0kg and a velocity of 18 m/s?
    6·1 answer
  • Which is an example of a physical change? wood rots. gasoline ignites. water evaporates. a nail rusts. description?
    9·2 answers
  • Kathy tests her new sports car by racing with Stan, an experienced racer. Both start from rest, but Kathy leaves the starting li
    11·1 answer
  • .....i need help with another......
    12·2 answers
  • Can you help me answer this?
    11·1 answer
  • Two Polaroids are aligned so that the initially unpolarized light passing through them is a maximum. At what angle should one of
    5·1 answer
  • Curious George is whirling a 2.0 kg bunch of bananas on a smooth floor in a circular path having a radius of 0.50 m. What force
    9·1 answer
  • Hi.
    11·1 answer
  • I just want to shift to another country to learn like London so who can tell me the progress​
    12·1 answer
  • The uniform rods AB and BC weigh 24 ky and kg, respectively,and the small wheel at C is of negligible weight. If the wheel ismov
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!