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3 years ago

What is the braking force needed to bring a 15kg car going 35 m/s to a complete stop in 5s?

Physics

1 answer:

Morgarella [4.7K]3 years ago

3 0

Need the acceleration take 35/5 to get 7
then multiply 15 by 7 to get 105N

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Spiderman, whose mass is 74.0 kg, is dangling on the free end of a 11.0-m-long rope, the other end of which is fixed to a tree l

Anestetic [448]

Answer:

W = -1844.513 J

Explanation:

GIVEN DATA:

mass of spider man is m 74 kg

vertical displacement if spider is 11 m

final displacement = 11 cos 60.6 = - 6.753 m

change in displacement is = -6.753 - (-11) = 4.25 m

gravity force act on spiderman is f = mg = 74 × 9.8 = 725.2 N

work done by gravity is $W = F \delta r cos\theta$

$W = 725.2 \times 4.25 \times cos 180$

where 180 is the angle between spiderman weight and displacement

W = -1844.513 J

7 0

3 years ago

What mass of ice (in g) can be melted if 27.2 kJ of thermal energy are added at the freezing point? Use molar mass = 18.02 g/mol

san4es73 [151]

Answer : The mass of ice melted can be, 3.98 grams.

Explanation :

First we have to calculate the moles of ice.

$Q=\frac{\Delta H}{n}$

where,

Q = energy absorbed = 27.2 kJ

$\Delta H$ = enthalpy of fusion of ice = 6.01 kJ/mol

n = moles = ?

Now put all the given values in the above expression, we get:

$27.2kJ=\frac{6.01kJ/mol}{n}$

$n=0.221mol$

Now we have to calculate the mass of ice.

$\text{Mass of ice}=\text{Moles of ice}\times \text{Molar mass of ice}$

Molar mass of ice = 18.02 g/mol

$\text{Mass of ice}=0.221mol\times 18.02g/mol=3.98g$

Thus, the mass of ice melted can be, 3.98 grams.

3 0

4 years ago

State the law of conservation of linear momentum using Newton's third law of deduce this

MArishka [77]

Answer:

Derivation of Conservation of Momentum

Applying Newton's third law, these two impulsive forces are equal and opposite i.e. is equal to the change in momentum of the first object. is equal to the change in momentum of the second object. This relation suggests that momentum is conserved during the collision.

Explanation:

Hope it helps!!!

7 0

3 years ago

A bug walking on the circular rim of a flower

Mekhanik [1.2K]

Given parameters;

Time taken to complete a lap = 8.667s

Radius of flower = 13.9cm

convert to SI unit of m, 100cm = 1m

13.9cm gives $\frac{13.9}{100}$ = 0.139m

Unknown = speed

To solve this problem, we need to first find the circumference of the flower.

Circumference of the circular flower = 2 π r

where r is the radius of the flower;

Circumference = 2 x 3.142 x 0.139 = 0.87m

Now to find the how fast the bug is travelling,

Speed = $\frac{distance}{time}$

Since the bug covered 1 lap, the distance is 0.87m

Now input the parameters and solve for speed;

Speed = $\frac{0.87}{8.667}$ = 0.1m/s

The bug is travelling at a speed of 0.1m/s

8 0

3 years ago

What characteristics do atoms of carbon-12, carbon-13, and carbon-14 have in common? 1. same number of electrons 2. same number

Rasek [7]

Answer:

The most common of these is carbon 12, 13, 14. All of these isotopes have the same atomic number but different mass numbers. Carbon has the atomic number of 6 which means that all isotopes have the same proton number. However, the number of neutrons is different, thus giving different mass numbers.

7 0

3 years ago