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4 years ago

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A 1500-kg car accelerates from 0 to 25 m/s in 7.0s with negligible friction and air resistance. What is the average power delive

red by the engine? (1 hp 746 W)

1 answer:

NARA [144]4 years ago

4 0

Answer:

90 hp

Explanation:

Power = work / time

P = ½ (1500 kg) (25 m/s)² / 7.0 s

P = 67,000 W

P = 90 hp

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A bike race against the clock takes place on a straight road. Yan drives at 37 km / h and he starts the course 30s before Christ

joja [24]

Given data:

Yan speed;

$u_1=37\text{ km/h}$

Christopher speed;

$u_2=38.9\text{ km/h}$

Christophe starts 30 s later than Yan. Therefore, Christophe takes 30 s less than Yan to reach the same distance.

Part (A)

The distance is given as,

$d=ut$

Let both Yan and Christophe meet at d distance from the start position. Therefore,

$u_1t=u_2(t-30)$

Substituting all known values,

$\begin{gathered} (37\text{ km/h})t=(38.9\text{ km/h})\times(t-30) \\ \frac{(37\text{ km/h})}{(38.9\text{ km/h})}=\frac{(t-30)}{t} \\ 0.95=1-\frac{30}{t} \\ \frac{30}{t}=1-0.95 \\ \frac{30}{t}=0.05 \\ t=\frac{30}{0.05} \\ t=600\text{ s} \end{gathered}$

Therefore, 600 s after Yan's departure Christophe will join him.

Part (B)

The distance is given as,

$d=u_1t$

Substituting all known values,

$\begin{gathered} d=(37\text{ km/h})\times(600\text{ s}) \\ =(37\text{ km/h})\times(600\text{ s})\times(\frac{1\text{ hr}}{3600\text{ s}}) \\ \approx6.17\text{ km} \end{gathered}$

Therefore, Christophe joins Yan after 6.17 km from the start.

3 0

1 year ago

A car with a momentum of 1200 kg.m/s with a mass of 600 kg hit a trash can which was on the side of the road,If the mass of tras

GuDViN [60]

Speaking that the trash can absorb the momentum. It only should go 5

4 0

3 years ago

Read 2 more answers

The base unit prefix used for 1,000× is _____. kilo milli centi deka

san4es73 [151]

Answer:

$\Large \boxed{\sf kilo}$

Explanation:

kilo is a prefix that means $1000$ of the base unit.

5 0

4 years ago

Un bloque de 750 kg es empujado hacia arriba por una pista inclinada 15º respecto de la horizontal. El coeficiente de rozamiento

kotegsom [21]

Answer:

4776.98 N is the minimum force to start the rise.

Explanation:

We can use the first Newton's law to find the minimum force to move the block.

So we will have:

$F-W_{x}-F_{f}=0$

Where:

F is the force
W(x) is the weight of the block in the x direction, W = mg*sin(15)
F(f) is the static friction force (F(f) = μN), μ is the static friction coefficient 0.4.

$F=W_{x}+F_{f}=mgsin(15)+\mu N$

$F=mgsin(15)+\mu mgcos(15)$

$F=mg(sin(15)+\mu cos(15))$

$F=750*9.81(sin(15)+0.4*cos(15))$

$F=4776.98 N$

Therefore 4776.98 N is the minimum force to move the block.

I hope it helps you!

8 0

3 years ago

Suppose that we replace the aluminum with a mystery metal and repeat the experiment in the video. As in the video, the mass of t

dimaraw [331]

Answer:

b) one-third as great.

Explanation:

As we know that same heat is supplied in this experiment

so we will have

$Q = ms\Delta T$

now we know that both are initially at same temperature

then their final temperatures are

$T_1 = 40 degree$

$T_2 = 80 degree$

now we have

$m_1s_1 (40 - 20) = m_2s_2(80 - 20)$

so we have

$m_2s_2 = \frac{20}{60} m_1s_1$

so heat capacity of mystery metal is 1/3 times that of water

6 0

3 years ago

Read 2 more answers