5. For what purpose do bats use ultrasonic waves?

A rocket is launched from the launch pad at a speed of 700 km/hr.

Juliette [100K]

Answer:

Explanation:

Vm = Δs/Δt

700km/h = Δs/1.5h

700 = Δs/1.5

$\frac{700}{1} = \frac{S}{1.5}$

S = 700 x 1.5

S = 1050 Km

*(S = Δs)

Answer: The rocket will have traveled 1050 Km

Hope this help ☺

5 0

3 years ago

Evidence on why we don’t hear solar eruptions on Earth.

sukhopar [10]

Because sound waves don't travel through the vaccume of space. Hope this helped

8 0

3 years ago

Read 2 more answers

A uniform disk of mass M = 4.9 kg has a radius of 0.12 m and is pivoted so that it rotates freely about its axis. A string wrapp

AlekseyPX

Answer:

(A) 2.4 N-m

(B) $0.035kgm^2$

(C) 315.426 rad/sec

(D) 1741.13 J

(E) 725.481 rad

Explanation:

We have given mass of the disk m = 4.9 kg

Radius r = 0.12 m, that is distance = 0.12 m

Force F = 20 N

(a) Torque is equal to product of force and distance

So torque $\tau =Fr$ , here F is force and r is distance

So $\tau =20\times 0.12=2.4Nm$

(B) Moment of inertia is equal to $I=\frac{1}{2}mr^2$

So $I=\frac{1}{2}\times 4.9\times 0.12^2=0.035kgm^2$

Torque is equal to $\tau =I\alpha$

So angular acceleration $\alpha =\frac{\tau }{I}=\frac{2.4}{0.035}=68.571rad/sec^2$

(C) As the disk starts from rest

So initial angular speed $\omega _{0}=0rad/sec$

Time t = 4.6 sec

From first equation of motion we know that $\omega =\omega _0+\alpha t$

So $\omega =0+68.571\times 4.6=315.426rad/sec$

(D) Kinetic energy is equal to $KE=\frac{1}{2}I\omega ^2=\frac{1}{2}\times 0.035\times 315.426^2=1741.13J$

(E) From second equation of motion

$\Theta =\omega _0t+\frac{1}{2}\alpha t^2=0\times 4.6+\frac{1}{2}\times 68.571\times 4.6^2=725.481rad$

3 0

3 years ago

If each washer has a mass of 4.9 g, then the mass of two washers in kilograms would be Given that F = ma, and if 4 washers are a

zysi [14]

Given that,

Mass of each washer = 4.9 g

We need to calculate the mass of two washers in kg

Using conversion of unit

Mass of each washer $m= 4.9\times10^{-3}\ Kg$

So, Mass of two washers is

$M=2\times m$

Put the value of m

$M=2\times4.9\times10^{-3}\ k$

$M=0.0098\ Kg$

If 4 washer are attached to the spring

We need to calculate the applied force on the car

Using formula of force

$F=mg$

Put the value into the formula

$F=4\times4.9\times10^{-3}\times9.8$

$F=0.192\ N$

Hence, (i), The mass of two washers is 0.0098 kg.

(ii). The applied force on the car is 0.192 N.

6 0

3 years ago

What is the general aerobic activity recommendation for an exercise frequency that is at least five days per week?

Fantom [35]

Explanation:

Minimum of aerobic activity 150 minutes, or a mix of moderates and intensive exercise 75 minutes of vigorous aerobic activity a week. We can extend this practice throughout the week with the instructions. Mild aerobic workouts might include practices like quick strolling or swimming, while activity like running can include strong aerobic activity.

4 0

3 years ago