Ask question

Ask question

All categories

1 year ago

6

A dog running to the right at 4 m/s sees a ball and accelerates steadily to catch it. The dog accelerates to the right at a rate

of 0.21 m/s^2 and catches the ball after 3.8s. What was the dogs velocity when it caught the ball? *Assume here that running to the right is positive and running to the left is negative.
A- 7.96
B- 10.569
C- 6.782
D- 4.798
E- none

1 answer:

antoniya [11.8K]1 year ago

6 0

Answer:

D.-4.798m/s

Explanation:

Greetings !

Given values

$u= 4ms \\ a = 0.21ms {}^{2} \\ t = 3.8sec$

Solve for V of the given expression

Firstly, recall the velocity-time equation

$v = u + at$

plug in known values to the equation

$v = (4) + (0.21)(3.8)$

solve for final velocity

$v = 4.792ms$

Hope it helps!

You might be interested in

61. A physics student has a single-occupancy dorm room. The student has a small refrigerator that runs with a current of 3.00 A

Mademuasel [1]

Answer:

Part a)

$percentage = 21.3$ %

Part b)

$percentage = 2.13 \times 10^{-5}$ %

Explanation:

As we know that total power used in the room is given as

$P = P_1 + P_2 + P_3 + P_4$

here we have

$P_1 = (110)(3) = 330 W$

$P_2 = 100 W$

$P_3 = 60 W$

$P_4 = 3 W$

$P = 330 + 100 + 60 + 3$

$P = 493 W$

Part a)

Since power supply is at 110 Volt so the current obtained from this supply is given as

$110\times i = 493$

$i = 4.48 A$

now resistance of transmission line

$R = \frac{\rho L}{A}$

$R = \frac{(2.8 \times 10^{-8})(10\times 10^3)}{\pi(4.126\times 10^{-3})^2}$

$R = 5.23 \ohm$

now power loss in line is given as

$P = i^2 R$

$P = (4.48)^2(5.23)$

$P = 105 W$

Now percentage loss is given as

$percentage = \frac{loss}{supply} \times 100$

$percentage = \frac{105}{493} \times 100$

$percentage = 21.3$ %

Part b)

now same power must have been supplied from the supply station at 110 kV, so we have

$110 \times 10^3 (i ) = 493$

$i = 4.48\times 10^{-3} A$

now power loss in line is given as

$P = i^2 R$

$P = (4.48 \times 10^{-3})^2(5.23)$

$P = 1.05 \times 10^{-4} W$

Now percentage loss is given as

$percentage = \frac{loss}{supply} \times 100$

$percentage = \frac{1.05 \times 10^{-4}}{493} \times 100$

$percentage = 2.13 \times 10^{-5}$ %

6 0

3 years ago

A spelunker is surveying a cave. she follows a passage 170 m straight west, then 250 m in a direction 45â east of south, and the

almond37 [142]

Im not sure but is the magnitude 160.8?

4 0

3 years ago

Use the drop-down menu to complete the statement.

SOVA2 [1]

Answer:

static discharge

Explanation:

I hope this helps

7 0

3 years ago

Read 2 more answers

They don't have an Astronomy Section and I believe that this falls the closest to Physics

Ksenya-84 [330]

The only thing we know of so far that can shift light to longer wavelengths is the "Doppler" effect. If the source and the observer are moving apart, then the observer sees wavelengths that are longer than they should be. If the source and the observer are moving toward each other, then the observer sees wavelengths that are shorter than they should be. It works for ANY wave ... sound, light, water etc. The trick is to know what the wavelength SHOULD be. If you know that, then you can tell whether you and the source are moving together or apart, and you can even tell how fast. If the lines in a star"s spectrum are at wavelengths that are too long, then from everything we know right now, the star and Earth are moving apart.

5 0

3 years ago

Which of the following is a true statement about learning?

Furkat [3]

Answer:

B. learning happens through experience and practice.

3 0

2 years ago