What are the SI units for acceleration?<br> a. m/s<br> b. m/s/s<br> c. N<br> d. kg

Radio devices are used for communication in space. Why

Elena-2011 [213]

Because radio waves can travel in space but sound waves cannot.

6 0

3 years ago

A ball with a weight of 2 N is attached to the end of a cord of length 2m . The ball is whirl in a vertical circle counterclockw

ZanzabumX [31]

Answer:

we agree with

Edgar: The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them.

Explanation:

Weight of the ball is given as

$W = 2N$

so we have

$m = \frac{W}{g}$

$m = 0.204 kg$

now tension force at the top is given as

$T_{top} = 7 N$

$T_{bottom} = 15 N$

Now at the top position by force equation we can say that ball will have two downwards forces

1) Tension force

2) Weight of the ball

so net force on the ball is given as

$F_{net} = T + W$

$F_{net} = 7 + 2 = 9 N$

So we agree with

Edgar: The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them.

8 0

3 years ago

A 70-kg boy is sitting 3 m from the ground in a tree. What is his gravitational potential energy

steposvetlana [31]

m x h x 9.8 m/s squared

70 kg x 3 m x 9.8 m/s squared= 2058 Joules

7 0

3 years ago

A wave has a speed of 30 m/s, a frequency of 6 Hz, and a wavelength of 5 m. If the wavelength remains constant, and the frequenc

mixer [17]

Answer: 60m/s

Explanation:

The wavespeed is the distance covered by the wave in one second. It is measured in metre per second, and represented by the symbol V

Wavespeed (V) = Frequency F x wavelength λ

i.e V = F λ

In the first case:

Wavespeed = 30 m/s

Frequency of sound = 6Hz

Wavelength = 5m

In the second case:

Wavespeed = ?

Frequency of sound = (2x 6Hz = 12Hz)

Wavelength = 5m (remains constant)

Apply V = F λ

Wavespeed = 12 Hz x 5m

Wavespeed = 60m/s

Therefore, when frequency is doubled, the speed is also doubled. Thus, the new speed of the wave is 60m/s

8 0

3 years ago

If the torque required to loosen a nut that

liraira [26]

Explanation:

τ = Fr

34 Nm = F (0.30 m)

F ≈ 113 N

7 0

2 years ago

What are the SI units for acceleration? a. m/s b. m/s/s c. N d. kg