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3 years ago

A crash test dummy is inside a test car moving at 55 km/h. How fast is the dummy moving relative to the seat he is sitting in?

2 answers:

8 0

The situation is exactly the same as YOUR speed relative to the seat you're sitting in, aboard the passenger jet flying at 500 mph with you in it.

kvasek [131]3 years ago

7 0

The dummy is moving with a speed 0 km/h relative to the seat in which it is sitting.

If the relative speed was non-zero, the dummy would move away from its seat, which contradicts the problem formulation.

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A motorcyclist drives around a bend with a 20 m radius, with a constant velocity of 3 m/s. The motorcyclist and the motorcycle h

Pavel [41]

Answer:

$a=0.45\ m/s^2$

Explanation:

Given that,

The radius of a bend, r = 20 m

Velocity of motorcyclist, v = 3 m/s

The combined mass of motorcyclist and the motorcycle is 50 kg

We need to find the motorcyclist’s centripetal acceleration. The formula used to find the centripetal acceleration is given by :

$a=\dfrac{v^2}{r}\\\\a=\dfrac{(3)^2}{20}\\\\a=0.45\ m/s^2$

So, the acceleration of the motorcyclist is $0.45\ m/s^2$ .

3 0

3 years ago

A cart of mass 6.0 kg moves with a speed of 3.0 m/s towards a second stationary cart with a mass of 3.0 kg. The carts move on a

katen-ka-za [31]

Answer:b

Explanation:

Given

mass of first cart $m_1=6 kg$

mass of second cart $m_2=3 kg$

velocity of first cart $v_1=3 m/s$

conserving momentum

$m_1v_1+m_2v_2=(m_1+m_2)v$

$6\times 3+3\times 0=(9)\cdot v$

$v=2 m/s$

Initial kinetic Energy $K.E._1=\frac{1}{2}m_1v_1^2+\frac{1}{2}m_2v_2^2$

$K.E._1=\frac{1}{2}\cdot 6\cdot 3^2+0$

$K.E._1=27 J$

Final Kinetic Energy

$K.E._2=\frac{1}{2}(m_1+m_2)v^2$

$K.E._2=\frac{1}{2}(6+3)\cdot 2^2=18 J$

Ratio of initial Kinetic Energy to the Final Kinetic Energy

$=\frac{27}{18}=1.5$

6 0

4 years ago

A marble statue has a mass of 6,200 grams and a volume of 2,296 cm3. What is the density of marble?

Elan Coil [88]

D= m/v
d= 6200/2296
density = about 2.7

6 0

3 years ago

What is the scientific method

MissTica

Answer:

Step 7- Communicate. Present/share your results. Replicate.

Step 1- Question.

Step 2-Research.

Step 3-Hypothesis.

Step 4-Experiment.

Step 5-Observations.

Step 6-Results/Conclusion

Explanation:

4 0

3 years ago

Read 2 more answers

Mixing baking soda with vinegar is an example of an oxidation-reduction

34kurt

Answer:

B. False

Explanation:

The reaction of baking soda and vinegar produces carbon dioxide gas. It is an example of precipitation reactions.

4 0

3 years ago