One newton force is the force needed to cause a

Radar is used to determine distances to various objects by measuring the round-trip time for an echo from the object. (a) How fa

BartSMP [9]

Answer

given,

Echo time = t = 1000 s

speed = ?

$v = \dfrac{d}{t}$

a) speed of electromagnetic wave

$c = \dfrac{d}{t}$

wave travels Venus two time

$c = \dfrac{2d}{t}$

$d = \dfrac{ct}{2}$

$d = \dfrac{3 \times 10^8\times 1000}{2}$

d = 1.5 x 10¹¹ m

b) now, echo time

$c = \dfrac{2d}{t}$

$t = \dfrac{2d}{c}$

$t = \dfrac{2\times 75}{3 \times 10^8}$

t = 5 x 10⁻⁷ s

8 0

3 years ago

A exercise ball is on a table 2.5 m above the ground. What is the mass

horsena [70]

Answer:

2.27kg

Explanation:

The Potential energy gained = Force gravity× Height

Force gravity on the ball is GPE/ height

56.8/2.5=22.72N

the mass = 22.72/10= 2.27kg

4 0

3 years ago

The specific heat of gold is 0.126 J/g°C. What mass of gold would change its temperature from 25.0 °C to 60.0 °C with the additi

fiasKO [112]

The amount of heat energy needed to increase the temperature of a substance by $\Delta T$ is given by:
 $Q=m C_s \Delta T$ 
where m is the mass of the substance, Cs is its specific heat capacity and $\Delta T$ is the increase in temperature of the substance.

In this problem, we have a certain mass m of gold, with specific heat capacity $C_s=0.126 J/g^{\circ}C$ , to which we add Q=2825 J of energy. Its temperature increases by $\Delta T=60-25=35 ^{\circ}C$ . Therefore, if we re-arrange the previous equation, we can find the mass of the block of gold:
 $m= \frac{Q}{C_s \Delta T} = \frac{2825J}{0.126\cdot 35}} =641 g$ 
So, the correct answer is B.

3 0

4 years ago

Read 2 more answers

BRAINLIEST WILL BE MARKED FOR THE FIRST ANSWER

slamgirl [31]

Answer:

The weight of the body in the new planet is 100 newtons.

Explanation:

From Newton's Law of Gravitation we find that gravitational force is directly proportional to mass of the planet and inversely proportional to the square of its radius. From this fact we can build the following relationship:

$\frac{F_{1}\cdot R_{1}^{2}}{M_{1}} = \frac{F_{2}\cdot R_{2}^{2}}{M_{2}}$ (1)

Where:

$F_{1}$ , $F_{2}$ - Gravitational force, measured in newtons.

$M_{1}$ , $M_{2}$ - Mass of planet, measured in kilograms.

$R_{1}$ , $R_{2}$ - Radius of the planet, measured in meters.

If we know that $F_{1} = 800\,N$ , $\frac{M_{2}}{M_{1}} = \frac{1}{2}$ and $\frac{R_{2}}{R_{1}} = 2$ , then the expected gravitational force in the new planet is:

$F_{2} = F_{1}\cdot \left(\frac{M_{2}}{M_{1}} \right)\cdot \left(\frac{R_{1}} {R_{2}}\right)^{2}$

$F_{2} = (800\,N)\cdot \left(\frac{1}{2} \right)\cdot \left(\frac{1}{2}\right)^{2}$

$F_{2} = 100\,N$

The weight of the body in the new planet is 100 newtons.

4 0

3 years ago

A block of mass m is attached to a spring of constant k, which oscillates over a table without friction. Which of the following

Fofino [41]

Answer:

3. Kinetic energy of the system is maximum when potential energy is minimum.

Explanation:

Given that

Mass of block= m

Spring constant =K

Table is friction less.

As we know that in oscillatory motion ,when kinetic energy is maximum then potential energy will become minimum.

At the mean position:

Kinetic energy is maximum.

Potential energy is minimum.

At the extreme position:

Kinetic energy is minimum.

Potential energy is maximum.

At the mean position velocity of block will be maximum that is why it have maximum kinetic energy and at the extreme position the velocity of block will be minimum that is why it have minimum kinetic energy.

So from above we can say that kinetic energy of the system is maximum when potential energy is minimum.

6 0

3 years ago