A car travels 98 km. It takes 34.92 minutes to complete the trip. What was the average speed?

Which term is used to describe the variety of inheritable traits in a species?

choli [55]

Genetic i think is it right?

7 0

3 years ago

Read 2 more answers

When hydrogen is burned in the presence of oxygen it will form water as per the equation: 2h2

Natasha_Volkova [10]

Answer:

B. In the first case, a combination reaction takes place and in the second case, a decomposition reaction takes place.

Explanation:

When hydrogen burns in oxygen, water is formed and when water is electrolysed then hydrogen and oxygen are produced. What type of a reaction takes place?

(i) In the first case,

(ii) In the second case?

A. In both the cases, i.e. (i) and (ii), a combination reaction takes place.

B. In the first case, a combination reaction takes place and in the second case, a decomposition reaction takes place.

C. In the first case, a combination reaction takes place and in the second case, a displacement reaction takes place.

D. In the first case, a displacement reaction takes place and in the second case, a decomposition reaction takes place.

Answer :

Hint: When hydrogen burns in air, H2H2 reacts with O2O2 to form water molecules. Here two reactants combine to form a single product. And, when water is electrolysed into hydrogen and oxygen, here a single compound decomposes into more than one product.

Complete step by step answer:

In the First case:

When hydrogen burns in oxygen, water is formed.

Hydrogen + Oxygen = Water

2H2+O2→2H2O2H2+O2→2H2O

When two reactants elements combine to form a single component, then this reaction is called the combination reaction. So, in this case, two reactants i.e. Hydrogen and oxygen combine to form a single product i.e. water molecules and heat is also released.

In the Second case:

When water is electrolysed then hydrogen and oxygen are produced.

2H2O→2H2+O22H2O→2H2+O2

When a single reactant is decomposed or broken down into two or more products, it is known as decomposition reaction. Here, a single reactant i.e. water, breaks or decomposes up to form two or more simple products i.e. hydrogen and oxygen. This decomposition reaction takes place by the action of electricity. So, we can see that in the first case, a combination reaction takes place and in the second case, a decomposition reaction takes place.

Therefore, the correct answer is option (B).

Note: Hydrogen is combustible and it burns with a popping sound in oxygen with an almost colourless flame to form water molecules and release heat. This reaction is highly exothermic. Hydrogen must be handled very carefully as the mixture of hydrogen and oxygen can be explosive when two are present in a particular ratio.

7 0

2 years ago

A 115 g hockey puck sent sliding over ice is stopped in 15.1 m by the frictional force on it from the ice.

Hoochie [10]

Answer:

(a) Ff = 0.128 N

(b μk = 0.1135

Explanation:

kinematic analysis

Because the hockey puck moves with uniformly accelerated movement we apply the following formulas:

vf=v₀+a*t Formula (1)

d= v₀t+ (1/2)*a*t² Formula (2)

Where:

d:displacement in meters (m)

t : time in seconds (s)

v₀: initial speed in m/s

vf: final speed in m/s

a: acceleration in m/s

Calculation of the acceleration of the hockey puck

We apply the Formula (1)

vf=v₀+a*t v₀=5.8 m/s , vf=0

0=5.8+a*t

-5.8 = a*t

a= -5.8/t Equation (1)

We replace a= -5.8/t in the Formula (2)

d= v₀*t+ (1/2)*a*t² , d=15.1 m , v₀=5.8 m/s

15.1 = 5.8*t+ (1/2)*(-5.8/t)*t²

15.1= 5.8*t-2.9*t

15.1= 2.9*t

t = 15.1 / 2.9

t= 5.2 s

We replace t= 5.2 s in the equation (1)

a= -5.8/5.2

a= -1.115 m/s²

(a) Calculation of the frictional force (Ff)

We apply Newton's second law

∑F = m*a Formula (3)

∑F : algebraic sum of the forces in Newton (N)

m : mass in kilograms (kg)

a : acceleration in meters over second square (m/s²)

Look at the free body diagram of the hockey puck in the attached graphic

∑Fx = m*a m= 115g * 10⁻³ Kg/g = 0.115g , a= -1.12 m/s²

-Ff = 0.115*(-1.115) We multiply by (-1 ) on both sides of the equation

Ff = 0.128 N

(b) Calculation of the coefficient of friction (μk)

N: Normal Force (N)

W=m*g= 0.115*9.8= 1.127 N : hockey puck Weight

g: acceleration due to gravity =9.8 m/s²

∑Fy = 0

N-W=0

N = W

N = 1.127 N

μk = Ff/N

μk = 0.128/1.127

μk = 0.1135

8 0

3 years ago

Two boats - Boat A and Boat B - are anchored a distance of 24 meters apart. The incoming water waves force the boats to oscillat

ozzi

Answer:

wavelength = 24 m

Period = 10 s

f = 0.1 Hz

Amplitude = 4 m

Explanation:

Wavelength:

Since the boats are at crest and trough, respectively at the same time. Hence, the horizontal distance between them is the wavelength of the wave:

wavelength = 24 m

Period:

The period is given as:

$Period = \frac{time}{no.\ of\ cycles} \\\\Period = \frac{10\ s}{1}\\\\$

Period = 10 s

Frequency:

The frequency is given as:

$f = \frac{1}{time\ period}\\\\f = \frac{1}{10\ s}\\\\$

f = 0.1 Hz

Amplitude:

Amplitude will be half the distance between extreme points, that is, crest and trough:

Amplitude = 8 m/2

Amplitude = 4 m

5 0

3 years ago

A car with mass 450 kg has a kinetic energy of 16,256 j. What is the speed of the car?

Vikentia [17]

Do you still need the answer ?

7 0

2 years ago