A 25 kg mass is accelerated by a force at a rate of 5 m/s2. What is the magnitude of the force that accelerates the man?

Which of the following terms relate to the meaning of "physical"?

zubka84 [21]

Body is definitely one of them

7 0

3 years ago

Running at maximum speed, it takes a boat times as long to go 10 miles upstream as it does to go 10 miles downstream. If the cur

Greeley [361]

Note: The question states the time to go upstream is a number of times (not explicitly written) the time to go downstream. We'll assume a general number N

Answer:

$\displaystyle v_b=\frac{N+1}{N-1}(4\ mph)$

Explanation:

Relative Speed

If a boat is going upstream against the water current, the true speed of motion is $v_b-v_w$ , being $v_b$ the speed of the boat and $v_w$ the speed of the water. If the boat is going downstream, the true speed becomes $v_b+v_w$ .

The question states the time to go upstream is a number of times N (not explicitly written) the time to go downstream. The speed of an object is computed as

$\displaystyle v=\frac{x}{t}$

Where x is the distance traveled and t the time taken for that. The time can be computed by

$\displaystyle t=\frac{x}{v}$

If $t_u$ is the time for the upstream travel and $t_d$ is the time for the downstream travel, then

$t_u=Nt_d$

Siince the same distance x= 10 miles is traveled in both cases:

$\displaystyle \frac{10}{v_b-v_w}=N\frac{10}{v_b+v_w}$

Simplifying and rearrangling

$v_b+v_w=N(v_b-v_w)$

Operating

$v_b+v_w=Nv_b-Nv_w$

Solving for $v_b$

$\displaystyle v_b=\frac{N+1}{N-1}v_w$

$If\ N=2,\ v_w=4\ mph$

$\displaystyle v_b=\frac{3}{1}(4)=12\ mph$

If N=3

$\displaystyle v_b=\frac{4}{2}v_w=2(4)=8\ mph$

We can use the required value of N to compute the speed of the boat as explained

7 0

3 years ago

Insect A moves 5.0 m/min and insect B moves

mezya [45]

Answer:

insect B by 12m

Explanation:

30min = 1800s (times by 60)

5m/min x 30min = 150m

9cm/s x 1800s = 16,200cm = 162m

162m - 150m = 12m

6 0

2 years ago

Heidi (39 kg) is walking her tiny chihuahua, Chaxi (5.60 kg), on the sidewalk. To encourage Chaxi along, Heidi pulls forward wit

Ivan

Answer:

The correct reaction force in response to Heidi's action force is:

c. The friction is equal to 660 N since the beam is not accelerating.

Explanation:

Heidi's action force does not affect the beam. Since friction resists the sliding or rolling of one solid object over another, there is no friction acting on the beam, in this respect. The reaction force is what makes the dog to move because it acts on it. According to Newton's Third Law of Motion, forces always come in action-reaction pairs. This Third Law states that for every action force, there is an equal and opposite reaction force. This means that the dog exerts some force on Heidi, as he pulls it "forward with a force of 9.55 N."

4 0

2 years ago

In the simplified version of Kepler's third law, P 2 = a3, the units of the orbital period P and the semimajor axis a of the ell

Orlov [11]

Answer:

The units of the orbital period P is years and the units of the semimajor axis a is astronomical units.

Explanation:

P² = a³ is the simplified version of Kepler's third law which governs the orbital motion of large bodies that orbit around a star. The orbit of each planet is an ellipse with the star at the focal point.

Therefore, if you square the year of each planet and divide it by the distance that it is from the star, you will get the same number for all the other planets.

Thus, the units of the orbital period P is years and the units of the semimajor axis a is astronomical units.

8 0

2 years ago