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Scilla [17]
3 years ago
5

Alice and Tom dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running

start and jumps with an initial horizontal velocity of 25 m/s. Neither person experiences any significant air resistance. Just as they reach the lake below.A) Alice reaches the surface the lake first. B) Tom of reaches the surface of the first. C) Alice and Tom will reach the surface of the lake at the same time. D) Information is not enough
Physics
1 answer:
crimeas [40]3 years ago
3 0

Answer:c

Explanation:

Given

Alice launches with horizontal velocity u=25\ m/s

Tom simply drops straight down from the edge

Time taken by both the person is same as they have same initial vertical velocity i.e. zero so the time taken to reach the ground is zero.

Although Alice will travel more horizontal distance compared to Tom.

Thus option c is correct

You might be interested in
If you lift two loads up one story, how much work do you do compared to lifting just one load up one story?
Daniel [21]

Answer:a

Explanation:

We have to lift the load two loads up one story, so energy required is

let m be the mass of each load and h is the height of each story

Energy E_1=2\times m\times g\times \h

E_1=2mgh

Here energy gained is the potential energy which depends upon the datum(floor).

For lifting one load up one story

Energy required

E_2=mgh

thus E_2 is half of E_1

So option a is correct                                

6 0
3 years ago
(b) How far from the surface will a particle go if it leaves the asteroid's surface with a radial speed of 1510 m/s? (c) With wh
makvit [3.9K]

Answers:

(a) 2509.98 m/s

(b) 397042.215 m

(c) 1917.76 m/s

Explanation:

The question is incomplete, please remember to write the whole question :) However, part (a) is written below:

(a) What is the escape speed on a spherical asteroid whose radius is 700 km  and whose gravitational acceleration at the surface is a_{g}=4.5 m/s^{2}

Knowing this, let's begin:

a) In this part we need to find the escape speed V_{e} on the asteroid:

V_{e}=\sqrt{\frac{2GM}{R}} (1)

Where:

G is the universal gravitational constant

M is the mass of the asteroid

R=700 km=700(10)^{3} m is the radius of the asteroid

On the other hand we know the gravitational acceleration is a_{g}=4.5 m/s^{2}, which is given by:

a_{g}=\frac{GM}{R^{2}} (2)

Isolating GM:

GM=a_{g}R^{2} (3)

Substituting (3) in (1):

V_{e}=\sqrt{\frac{2a_{g}R^{2}}{R}}=\sqrt{2a_{g}R} (4)

V_{e}=\sqrt{2(4.5 m/s^{2})(700(10)^{3} m)} (5)

V_{e}=2509.98 m/s (6) This is the escape velocity

b) In this part we will use the Conservation of mechanical energy principle:

E_{o}=E_{f} (7)

Being:

E_{o}=K_{o}+U_{o}=\frac{1}{2}m V^{2} - \frac{GMm}{R} (8)

E_{f}=K_{f}+U_{f}=0 - \frac{GMm}{R+h} (9)

Where:

E_{o} is the initial mechanical energy

E_{f} is the final mechanical energy

K_{o} is the initial kinetic energy

K_{f}=0 is the final kinetic energy

U_{o} is the initial gravitational potential energy

U_{f} is the final gravitational potential energy

m is the mass of the object

V=1510 m/s is the radial speed of the object

h is the distance above the surface of the object

Then:

\frac{1}{2}m V^{2} - \frac{GMm}{R}=- \frac{GMm}{R+h} (10)

Isolating h:

h=\frac{2 a_{g} R^{2}}{2a_{g}R-V^{2}}-R (11)

h=\frac{2 (4.5 m/s^{2}) (700(10)^{3} m)^{2}}{2(4.5 m/s^{2})(700(10)^{3} m)-(1510 m/s)^{2}}-700(10)^{3} m (11)

h=397042.215 m (12) This is the distance above the asteroid's surface

c) We will use the Conservation of mechanical energy principle again, but now the condition is that the object is dropped at a distance h=981.8 km=981.8(10)^{3} m. This means that at the begining the object only has gravitational potential energy and then it has kinetic energy and gravitational potential energy:

\frac{-GMm}{R+h}=\frac{-GMm}{R}+\frac{1}{2}mV^{2} (13)

Isolating V:

V=\sqrt{2a_{g} R(1-\frac{R}{R+h})} (14)

V=\sqrt{2(4.5 m/s^{2}) (700(10)^{3} m)(1-\frac{700(10)^{3} m}{700(10)^{3} m+981.8(10)^{3} m})} (15)

Finally:

V=1917.76 m/s

7 0
3 years ago
How is acceleration calculated?
steposvetlana [31]

Answer:

Acceleration is the change in velocity divided by time

Explanation:

This is the correct answer because distance divided by time is the position. Speed multiplied by time is the distance. And acceleration is not just velocity, but the change in velocity over time.

4 0
3 years ago
Read 2 more answers
In noisy factory environments, it's possible to use a loudspeaker to cancel persistent low-frequency machine noise at the positi
Vaselesa [24]

Answer:

7.39 m or 3.61 m

Explanation:

\lambda = Wavelength

f = Frequency = 90 Hz

v = Speed of sound = 340 m/s

Path difference of the two waves is given by

s_1-s_2=\frac{\lambda}{2}

Velocity of wave

v=f\lambda\\\Rightarrow \lambda=\frac{v}{f}\\\Rightarrow \lambda=\frac{340}{90}\\\Rightarrow \lambda=3.78\ m

s_1=s_2\pm\frac{\lambda}{2}\\\Rightarrow s_1=5.5\pm \frac{3.78}{2}\\\Rightarrow s_1=7.39\ m, 3.61\ m

So, the location from the worker is 7.39 m or 3.61 m

7 0
3 years ago
This graph indicates that the kinetic energy of an object is increasing. What is the most reasonable explanation for this observ
soldi70 [24.7K]

B) The object's velocity doubled.

Explanation:

The graph is missing: find it in attachment.

The kinetic energy of an object is the energy possessed by the object due to its motion. It is calculated as

K=\frac{1}{2}mv^2

where

m is the mass of the object

v is the velocity of the object

We notice that:

  • The  kinetic energy is directly proportional to the mass
  • The kinetic energy is proportional to the square of the velocity

In the graph, one of the two quantities (either mass or speed) is represented on the x-axis, while the quantity on the y-axis is the kinetic energy.

First of all, we notice that the relationship is not linear: this means that the quantity on the x-axis cannot be the mass, so it must be the velocity.

Moreover, we notice that when the quantity on the x-axis increases from 1 to 2 (so, it doubles), the kinetic energy increases by a factor of 4. This means that the object's velocity has doubled, therefore

B) The object's velocity doubled.

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

5 0
3 years ago
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