Anyone know this question?

At one particular moment, a 19.0 kg toboggan is moving over a horizontal surface of snow at 4.00 m/s. After 7.00 s have elapsed,

Lina20 [59]

Answer:

10.86 N

Explanation:

Let the average frictional force acting on the toboggan be 'f' N.

Given:

Mass of toboggan (m) = 19.0 kg

Initial velocity (u) = 4.00 m/s

Final velocity (v) = 0 m/s

Time for which friction acts (Δt) = 7.00 s

Now, change in momentum is given as:

$\Delta p =Final\ momentum-Initial\ momentum\\\\\Delta p=mv-mu\\\\\Delta p=19.0\ kg(0-4.00)\ m/s\\\\\Delta p=-76.00\ Ns$

Now, we know that, change in momentum is equal to the impulse acting on the body. So,

Impulse is, $J=\Delta p=-76.00\ Ns$

Now, we know that, impulse is also given as the product of average force and the time interval for which it acts. So,

$J=f\times \Delta t$

Rewriting the above equation in terms of 'f', we get:

$f=\dfrac{J}{\Delta t}$

Plug in the given values and solve for 'f'. This gives,

$f=\frac{-76.00\ Ns}{7.00\ s}\\\\f=-10.86\ N$

Therefore, the magnitude of frictional force is $|f|=|-10.86\ N|=10.86\ N$

3 0

3 years ago

Two charges of magnitude +q are separated by a distance d. Assuming there are no changes to anything else, but the charges are s

erma4kov [3.2K]

Answer:

The Coulomb force between them will decrease by a factor of 1/9

Explanation:

The Coulomb's force acting between two particles of equal charge, q, separated by a distance, d, is given as:

$F = \frac{kq^2}{d^2}$

where k = Coulomb's constant

If they are separated by 3 times their current distance, the new distance becomes 3d. Hence, the Coulomb force acting between them becomes:

$F_n = \frac{kq^2}{(3d)^2}\\ \\\\F_n = \frac{kq^2}{9d^2} \\\\\\F_n = \frac{1}{9} F$

Hence, the Coulomb force decreases by a factor of 1/9.

4 0

3 years ago

Read 2 more answers

Which of the following statements best summarizes the first paragraph of this passage?

Fed [463]

Read the paragraph multiple times and find the main ideas and supporting details. Find what it is mostly about and compare the information you have to the statements and select the one most like yours. This is the best I can do without seeing any of the choices and the paragraph. Hope this helps! :)

4 0

4 years ago

Read 2 more answers

Can there be situation when velocity is constant but speed is not

klasskru [66]

Answer:

no I don’t think there can be so my answer is No.

Okay then yes sorry that I must have gotten it wrong before.

Explanation:

4 0

3 years ago

Read 2 more answers

A meter stick whose mass is 330 grams lies on ice. You pull at one end of the meter stick, at right angles to the stick, with a

Sophie [7]

Answer:

initial magnitude will be 9 N and direction will be to the right

Explanation:

force= 9N

mass m= 330 grams

acceleartion = a

from newtons 2nd law of motion we write

$F= \frac{\mathrm{dP} }{\mathrm{d} t}$

dP is the chage in momentum dt is time taken and F is the Force applied

$9N= \frac{\mathrm{dP} }{\mathrm{d} t}$

this shows that the rate of change of momentum is 9 N

we also know that F= ma

putting values we get

$9= 0.330\times a$

a= 27.27 m/sec^2

The direction of acceleration will along the direction of force applied. So will be the direction of change momentum as in F=ma, mass is the scalar quantity and direction of force dictates the direction of motion. Hence, initial magnitude will be 9N and direction will be to the right

3 0

3 years ago