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
Serga [27]
3 years ago
9

With what minimum speed must you toss a 200 g ball straight up to just touch the 14-m-high roof of the gymnasium if you release

the ball 1.3 m above the ground? solve this problem using energy.
Physics
1 answer:
Brut [27]3 years ago
8 0
When they say use energy, you want to use

Total energy = potential energy + kinetic energy = mgh + 1/2mv²

I assume you mean 200 g ball,

so, we know the total distance traveled is going to be 13 - 1.3 = 11.7 m

If the ball just makes it to the top ( 13 m ) , then the ball will stop moving and the kinetic energy will be 0,

therefore, the potential energy at the top will be the total energy of the system = mgh

from this, we say that mgh = 1/2mv² solve for v

<span> v = sqrt (2gh) = 15.2 m/s </span>
You might be interested in
A block of ice with mass 5.50 kg is initially at rest on a frictionless, horizontal surface. A worker then applies a horizontal
Yuki888 [10]

Answer:

A) 3.13 m/s

B) 5.34 N

C) W = 26.9 J

Explanation:

We are told that the position as a function of time is given by;

x(t) = αt² + βt³

Where;

α = 0.210 m/s² and β = 2.04×10^(−2) m/s³ = 0.0204 m/s³

Thus;

x(t) = 0.21t² + 0.0204t³

A) Velocity is gotten from the derivative of the displacement.

Thus;

v(t) = x'(t) = 2(0.21t) + 3(0.0204t²)

v(t) = 0.42t + 0.0612t²

v(4.5) = 0.42(4.5) + 0.0612(4.5)²

v(4.5) = 3.1293 m/s ≈ 3.13 m/s

B) acceleration is gotten from the derivative of the velocity

a(t) = v'(t) = 0.42 + 2(0.0612t)

a(4.5) = 0.42 + 2(0.0612 × 4.5)

a(4.5) = 0.9708 m/s²

Force = ma = 5.5 × 0.9708

F = 5.3394 N ≈ 5.34 N

C) Since no friction, work done is kinetic energy.

Thus;

W = ½mv²

W = ½ × 5.5 × 3.1293²

W = 26.9 J

6 0
3 years ago
Joshua was driving to a friend’s house to study. During his trip, he started on pavement. At one point, he hit an ice patch on t
Tems11 [23]

Answer:

b. Friction decreased when he went from pavement to ice and then increased two more times.

Explanation:

Frictional force depends on the normal force of the surface and a friction coefficient.

F_{f} = -\mu N

Since we're talking about the same car, the value of N will remain constant whereas μ will represent the change in the frictional coefficient of the surface. Now we consider the different surfaces, cars will slide in an icy road which means that the frictional coefficient is smaller than the pavement.

After Joshua returns to the pavement road, the resulting frictional force increases and will do so one more time when he reaches the gravel road. Gravel roads have greater frictional coefficients than pavement roads which means the frictional force will increase a second time.

7 0
3 years ago
Read 2 more answers
A boy throws a snowball straight up in the air with an initial speed of 4.50 ft/s from a position 4.00 ft above the ground. The
IgorC [24]

Answer:

a) 0.658 seconds

b) 0.96 inches

Explanation:

v=u+at\\\Rightarrow 0=4.5-32.1\times t\\\Rightarrow \frac{-4.5}{-32.1}=t\\\Rightarrow t=0.14 \s

Time taken by the ball to reach the highest point is 0.14 seconds

s=ut+\frac{1}{2}at^2\\\Rightarrow s=4.5\times 0.14+\frac{1}{2}\times -32.1\times 0.14^2\\\Rightarrow s=0.315\ ft

The highest point reached by the snowball above its release point is 0.315 ft

Total height the snowball will fall is 4+0.315 = 4.315 ft

s=ut+\frac{1}{2}at^2\\\Rightarrow 4.315=0t+\frac{1}{2}\times 32.1\times t^2\\\Rightarrow t=\sqrt{\frac{4.315\times 2}{32.1}}\\\Rightarrow t=0.518\ s

The snowball will reach the bank at 0.14+0.518 = 0.658 seconds after it has been thrown

v=u+at\\\Rightarrow v=0+32.1\times 0.518\\\Rightarrow v=16.62\ ft/s

v^2-u^2=2as\\\Rightarrow s=\frac{v^2-u^2}{2a}\\\Rightarrow s=\frac{0^2-16.62^2}{2\times -100\times 3.28}\\\Rightarrow s=0.42\ ft

The snowball goes 0.5-0.42 = 0.08 ft = 0.96 inches

8 0
3 years ago
How do you find the water pressure at the bottom of the 55-m-high water tower?
svp [43]
-- What's the volume of a cylinder with radius=1m and height=55m ?

         ( Volume of a cylinder = π R² h )

-- How much does that volume of water weigh ?

            1 liter of water = 1 kilogram of mass
            Weight = (mass) x (acceleration of gravity) 

-- What's the area of the bottom of that 1m-radius cylinder ?

       Pressure  =  (force) / (area)
5 0
3 years ago
How do molecules at warm temperatures differ from molecules at cool temperatures? Question 1 options: At warm temperatures, mole
yaroslaw [1]

Answer:

A. At warm tempetures, molecules move around more.

Explanation:

I'm at k12 and I just took the test got it right. Physical Science: Unit 2 Test

7 0
3 years ago
Read 2 more answers
Other questions:
  • Which statement is most likely correct?
    8·2 answers
  • li A 1500 kg weather rocket accelerates upward at IO mis 2. It explodes 2.0 s after liftoff and breaks into two fragments, one t
    8·1 answer
  • a 0.25 kg arrow is moving at 5 m/s and hits a 0.10 kg apple. The apple sticks to the arrow, and both move to the right together.
    8·1 answer
  • ID: A
    5·1 answer
  • You ride your skateboard to school and tell all your friends your rode at speed of 25 miles per hour. They know this cannot be t
    7·2 answers
  • What are atoms composed of
    12·2 answers
  • Science is hard sometimes help please!
    10·1 answer
  • A car moves in a straight line at a speed of 68.5 km/h. How far (in km) will the car move in 5.45 minutes at this speed?
    8·1 answer
  • Creative
    15·2 answers
  • How long did it take for a message sent from earth to reach the first astronauts?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!