Ask question

Ask question

All categories

2 years ago

11

A fast Humvee drove from Desert A to Desert B. for the first 12 hours and traveled at an average speed of 185 km/h. For the next

13 hours, it travelled at an average speed of 160 km/h. What was the average speed of the whole journey?

1 answer:

FromTheMoon [43]2 years ago

8 0

Answer:

The value is $v_t = 172 \ km/h$

Explanation:

From the question we are told that

The average speed for the first 12 hours is $u = 185 km/h$

The average speed for the next 13 hours is $v = 160 \ km/h$

Generally the total time taken is mathematically represented as

$t_t = 12 + 13$

=> $t_t = 25 \ h$

The distance covered in the first movement is

$D = u * 12$

$D = 185 * 12$

$D = 2220 \ km$

The distance covered in the first movement is

$d= v * 13$

$d = 160 * 13$

$d = 2080 \ km$

The total distance traveled is

$D_t = D + d$

$D_t = 2220 +2080$

$D_t = 4300 \ km$

The average of the whole journey is

$v_t = \frac{D_t}{t_t}$

$v_t = \frac{4300}{25}$

$v_t = \frac{4300}{25}$

$v_t = 172 \ km/h$

You might be interested in

Why is it important to be able to trace the pole connection on a meter back to the same type of pole at the electrical source?

lozanna [386]

Answer:

Explanation:

A grounded wire is sometimes strung along the tops of the towers to provide lightning protection.

In areas where the neutral is grounded or earthed, it is essential to endure that the neutral and the live or hot wires are not confused for each other.

When this happens, the fuses on the transformer will not operate unless the fault is very close to the transformer. The fuses in the consumer's intake box, will not operate.

6 0

3 years ago

Several springs are connected as illustrated below in (a). Knowing the individual springs stiffness k1 = 20 N/m, k2 = 30 N/m, k3

Hatshy [7]

Answer:

The equivalent stiffness of the string is 8.93 N/m.

Explanation:

Given that,

Spring stiffness is

$k_{1}=20\ N/m$

$k_{2}=30\ N/m$

$k_{3}=15\ N/m$

$k_{4}=20\ N/m$

$k_{5}=35\ N/m$

According to figure,

$k_{2}$ and $k_{3}$ is in series

We need to calculate the equivalent

Using formula for series

$\dfrac{1}{k}=\dfrac{1}{k_{2}}+\dfrac{1}{k_{3}}$

$k=\dfrac{k_{2}k_{3}}{k_{2}+k_{3}}$

Put the value into the formula

$k=\dfrac{30\times15}{30+15}$

$k=10\ N/m$

k and $k_{4}$ is in parallel

We need to calculate the k'

Using formula for parallel

$k'=k+k_{4}$

Put the value into the formula

$k'=10+20$

$k'=30\ N/m$

$k_{1}$ ,k' and $k_{5}$ is in series

We need to calculate the equivalent stiffness of the spring

Using formula for series

$k_{eq}=\dfrac{1}{k_{1}}+\dfrac{1}{k'}+\dfrac{1}{k_{5}}$

Put the value into the formula

$k_{eq}=\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{35}$

$k_{eq}=8.93\ N/m$

Hence, The equivalent stiffness of the string is 8.93 N/m.

3 0

3 years ago

A ball, which has a mass of 1.25 kg, is thrown straight up from the top of a building 225 meters tall with a velocity of 52.0 m/

Anastasy [175]

First we will find the speed of the ball just before it will hit the floor

so in order to find the speed of the cart we will first use energy conservation

$KE_i + PE_i = KE_f + PE_f$

$\frac{1}{2}mv_i^2 + mgh = \frac{1}{2}mv_f^2 + 0$

$\frac{1}{2}(1.25)(52)^2 + 1.25(9.8)(225) = \frac{1}{2}(1.25)v_f^2$

So by solving above equation we will have

$v_f = 84.3 m/s$

now in order to find the momentum we can use

$P = mv$

$P = 1.25 \times 84.3$

$P = 105.4 kg m/s$

3 0

3 years ago

Explain why the shortening velocity became slower as the load became heavier in this experiment. how well did the results compar

valkas [14]

<span>The shortening velocity refers to the speed of the contraction from the muscle shortening while lifting a load. Maximal shortening velocity is only attained with a minimal load. With a light load, the shortening velocity is at its Maximal shortening velocity. When the weight is heavy, the speed in which the muscle lifts the weight decreases in speed at a slower velocity.</span>

6 0

2 years ago

3. Consider a locomotive and the rest of a freight train to be a single object. Suppose the locomotive is pulling the train up a

Nonamiya [84]

Answer:

Action - Pulling up the train.

Reaction - Friction on the locomotive

Explanation:

Locomotive is pulling the train upwards ,

Which is the action force applied by the locomotive,

As a reaction locomotive will be pulled by the train which is the reaction of pulling

Now, considering it as a action on locomotive , friction force will act on it as a reaction upwards which will result to move it upwards.

For train action is pulling up by locomotive and reaction will be friction acting on it downwards.

6 0

2 years ago