A ball is thrown so that its speed increases by 20 m/s in 10 seconds. What is the ball’s acceleration?

Andrews [41]

Answer:

Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere.

Explanation:

Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. Closer to the horizon, the sky fades to a lighter blue or white.

5 0

3 years ago

Read 2 more answers

A 45.0 g hard-boiled egg moves on the end of a spring with force constant 25.0 N/m. Its initial displacement 0.500 m. A damping

leva [86]

Answer:

0.02896 kg/s

Explanation:

$A_1$ = Initial displacement = 0.5 m

$A21$ = Final displacement = 0.1 m

t = Time taken = 0.5 s

m = Mass of object = 45 g

Displacement is given by

$x=Ae^{-\dfrac{b}{2m}t}cos(\omega t+\phi)$

At maximum displacement

$cos(\omega t+\phi)=1$

$\\\Rightarrow A_2=A_1e^{-\dfrac{b}{2m}t}\\\Rightarrow \dfrac{A_1}{A_2}=e^{\dfrac{b}{2m}t}\\\Rightarrow ln\dfrac{A_1}{A_2}=\dfrac{b}{2m}t\\\Rightarrow b=\dfrac{2m}{t}\times ln\dfrac{A_1}{A_2}\\\Rightarrow b=\dfrac{2\times 0.045}{5}\times ln\dfrac{0.5}{0.1}\\\Rightarrow b=0.02896\ kg/s$

The magnitude of the damping coefficient is 0.02896 kg/s

6 0

3 years ago

Two charges separated by one meter exert a 9 N force on each other. If the charges are pushed to a 3 meter separation, the force

tamaranim1 [39]

Answer:

False

Explanation:

The formula of force that exists between two charges is expressed as;

F = kq1q2/r²

If two charges separated by one meter exert a 9 N force on each other, the;

9 = kq1q2/1²

9 = kq1q2 ..... 1

If the charges are pushed to a 3 meter separation, then;

F = kq1q2/3²

F = kq1q2/9 .... 2

Divide both equations;

9/F = (kq1q2)/ kq1q2/9

9/F = kq1q2 * 9/ kq1q2

9/F = 9

F = 9/9

F = 1N

Hence if the charges are pushed to a 3 meter separation, then the force on EACH charge will be 1N. Hence the answer is False

3 0

2 years ago

A 60kg bicyclist (including the bicycle) is pedaling to the

Fittoniya [83]

a) 4 forces

b) 186 N

c) 246 N

Explanation:

a)

Let's count the forces acting on the bicylist:

1) Weight ( $W=mg$ ): this is the gravitational force exerted on the bicyclist by the Earth, which pulls the bicyclist towards the Earth's centre; so, this force acts downward (m = mass of the bicyclist, g = acceleration due to gravity)

2) Normal reaction (N): this is the reaction force exerted by the road on the bicyclist. This force acts vertically upward, and it balances the weight, so its magnitude is equal to the weight of the bicyclist, and its direction is opposite

3) Applied force ( $F_A$ ): this is the force exerted by the bicylicist to push the bike forward. Its direction is forward

4) Air drag ( $R$ ): this is the force exerted by the air on the bicyclist and resisting the motion of the bike; its direction is opposite to the motion of the bike, so it is in the backward direction

So, we have 4 forces in total.

b)

Here we can find the net force on the bicyclist by using Newton's second law of motion, which states that the net force acting on a body is equal to the product between the mass of the body and its acceleration:

$F_{net}=ma$