Ask question

Ask question

All categories

3 years ago

11

A life preserver is thrown from an helicopter straight down to a person in distress. The initial velocity of the life preserver

is 1.60 m/s and it takes 2.3 s to reach the water. (a) List the knowns in this problem. (b) How high above the water was the preserver released? Note Ignore air resistance.

1 answer:

Leno4ka [110]3 years ago

6 0

Answer:29.627 m

Explanation:

Given

Initial velocity of life preserver(u) is 1.6 m/s

it takes 2.3 s to reach the water

using equation of motion

v=u+at

$v=1.6+9.81\times 2.3$

v=24.163 m/s

Let s be the height of life preserver

$v^2-u^2=2gs$

$24.163^2-1.6^2=2\times 9.81\times s$

$s=\frac{581.29}{2\times 9.81}$

s=29.627 m

You might be interested in

At a speed of 60 mph, how far does your car travel in 3 seconds

Viefleur [7K]

One of the many random useless factoids that I carry around
in my head is the factoid that 60 miles per hour is equivalent
to exactly 88 feet per second.

So in three seconds at that speed, you would cover exactly

(3 x 88) = 264 feet.

4 0

3 years ago

When you strike two tuning forks simultaneously, you hear three beats per second. The frequency of the first tuning fork is 440

tekilochka [14]

Answer:4

Explanation:

Given

Frequency of beats is 3 beats per second

Frequency of first tuning fork is $f_1=440\ Hz$

Beat frequency is difference in the frequency of tuning forks i.e.

either $f_1-f_2$ or $f_2-f_1 =3$

so $f_2=3+440=443\ Hz$

or

$f_2=440-3=437\ Hz$

so there is not enough information given to decide.

5 0

3 years ago

Read 2 more answers

A point charge q1 is held stationary at the origin. A second charge q2 is placed at point a, and the electric potential energy o

likoan [24]

Answer:

$U_{b}=+7.3*10^{-8}J$

Explanation:

Given data

Electric potential at point a is Ua=5.4×10⁻⁸J

q₂ moves to point b where a negative work done on it $W_{a-b}=-1.9*10^{-8}J$

Required

Electric potential energy Ub

Solution

When a particle moves from a point where the potential is Ua to a point where it is Ub the change in potential energy is equal to work done where the force exerted on the charge is conservative and work done is given by:

$W_{a-b}=U_{a}-U_{b}\\U_{b}=U_{a}-W_{a-b}$

Now substitute the given values

So

$U_{b}=5.4*10^{-8}J-(-1.9*10^{-8}J)\\U_{b}=+7.3*10^{-8}J$

3 0

3 years ago

In Fig.25-46,how much charge is stored on the parallel-plate capacitors by the 12.0 V battery? One is filled with air,and the ot

Fittoniya [83]

Answer:

$Q=7.9\times 10^{-10}\ C$

Explanation:

Given that

V= 12 V

K=3

d= 2 mm

Area=5.00 $ 10#3 m2

Assume that

$ = Multiple sign

# = Negative sign

$A=5\times 10^{-3}\ m^2$

We Capacitance given as

For air

$C_1=\dfrac{\varepsilon _oA}{d}$

$C_1=\dfrac{\varepsilon _oA}{d}$

$C_1=\dfrac{8.85\times 10^{-12}\times 5\times 10^{-3}}{2\times 10^{-3}}$

$C_1=2.2\times 10^{-11}\ F$

$C_2=\dfrac{K\varepsilon _oA}{d}$

$C_2=\dfrac{3\times 8.85\times 10^{-12}\times 5\times 10^{-3}}{2\times 10^{-3}}\ F$

$C_2=6.6\times 10^{-11}\ F$

Net capacitance

C=C₁+C₂

$C=8.8\times 10^{-11}\ F$

We know that charge Q given as

Q= C V

$Q=12\times 6.6\times 10^{-11}\ C$

$Q=7.9\times 10^{-10}\ C$

6 0

3 years ago

Particles with more energy move ___ than particles with less energy?

Hitman42 [59]

Particle with more energy move SLOWER than particles with less energy.

8 0

3 years ago

Read 2 more answers